PHOTOPRODUCTION OF po0 IESONS ON COCPLEX NUCLEI by GARY HILTON SANDERS A.B., Columbia University (1967) SUM1ITTED IN PARTIAL FULFILUEI\l' OF THlE RETQUIIRiENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPIHY at the MASSACHUSETTS INSTITUTE OF TEC2HNOLOGY June, 1971 Signature of Author., ....... / Certified by ............ .................. ......................... Department of Physics, ....... .. .... .... ...... .. ..... "'" "' June, 1971 Thesis Suervisor. .......... *e ' * *e **o*" Chairman, Department Ccmnmittee on Graduate Students Archives APSS. INST. APR 28 1971 eA R I F- -2- ABSTRACT PHOTOPRODUCTION OF p0 MESONS ON COMPLEX NUCLEI GARY HILTON SANDERS Submitted to the Department of Physics, March, 1971, in partial fulfillment of the requirements for the degree of Doctor of Philosophy. An experiment was performed on the reaction y + A + A + pO + A + irt++ f- at the DESY 7.5 GeV electron synchrotron. Using a double arm magnetic spectrometer, approximately 106 dipion events were detected on thirteen complex nuclei covering a range from Beryllium to Uranium. The events were in a kinematic region defined by 20 intervals in dipion mass from 400 to 1000 MeV/c 2 , 10 intervals in the po resonance momentum from 3.5 to 7 GeV/c, and 20 intervals in the ;ransverse momentum transfer from 0.0 to -0.04 (GeV/c) . The data were corrected for systematic effects and differential cross-sections da/dndm(A,m,p,t) were extracted, revealing the predominant dynamical features of the data. Further analysis was carried out using current models for photoproduction and scattering on complex nuclei. The aim of this analysis ,was to: 1) study nuclear density distributions by fitting the t-dependence of the crosssections for each A to determine the nuclear radii seen by the po meson. 2) extract the absolute and relative forward po production cross-sections by fixing A, p, and t and studying the dipion spectrum as a function of -3invariant mass. This gives a determination of the po line-shape and background. 3) extract the po-nucleon cross-section apN and the y-p coupling constant y 2 /4r. pN By studying the nuclear density p distributions and the A-dependence of the production cross-sections, one determines the rate of reabsorption of po by nuclear matter and the effective single-nucleon forward production cross- section Ifo12 and the two quantities above in a self-consistent manner. Results of the analysis are: a) Woods-Saxon radii R(A) = (1.12+0.02)A1 '3 b) apN = 26.7 ± 2.0 mb c) y2 /4f = 0.57 ± 0.10 Cross-sections and resonance parameters are detailed in the text. Thesis supervisor: S.C.C. Ting Title: Professor of Physics -4- THE AUTHOR Gary Hilton Sanders was born in New York City on August 27, 1946. His early education was in the New York public school system. He received his high school diploma from Stuyvesant High School in June, 1963. At Columbia University, majoring in physics, working as an assistant in the Columbia Radiation Labs, and being caught up in the social and political milieu of Morningside Heights, combined to make four very rich and rewarding years. He received his A.B. in June, 1967. As a graduate student, research assistant and New York State Regents Fellow at M.I.T., he did course work for one year and in June, 1968 went to the Deutsches Elektronen Synchrotron in Hamburg to join the M.I.T.-DESY collaboration, where he spent the next two and one half years participating in photoproduction experiments listed in the bibliography below, and writing this thesis. -5- PUBLICATIONS 1. H. Alvensleben et al,"Validity of Quantum Electrodynamics at Extremely Small Distances", Physical Review Letters 21, 1501 (1968). 2. H. Alvensleben et al,"Validity of Quantum Electrodynamics at Extremely Small Distances", Proceedings of XIV International Conference on High Energy Physics, Vienna, September 1968, paper 958. 3. H. Alvensleben et al,"Photoproduction of Charged Pion Pairs on Protons", Physical Review Letters 23, 1058 (1969). 4. H. Alvensleben et al, Abstract No. 163, Fourth International Symposium on Electron and Photon Interactions at High Energies, Liverpool, September, 1969. 5. H. Alvensleben et al,"Photoproduction of Charged Pion Pairs on Protons", Proceedings of the International Seminar, Dubna, U.S.S.R., September 1969. 6. H. Alvensleben et al,"Leptonic Decays of Vector Mesons: The Observation of Coherent Interference Pattern Between p-w Decays", Proceedings of the International Seminar, Dubna, U.S.S.R.,September 1969. 7. H. Alvensleben et al,"On the Photoproduction of -6- Neutral Rho Mesons from Complex Nuclei",Proceedings of the International Seminar, Dubna, U.S.S.R. September, 1969. 8. H. Alvensleben et al,"Photoproduction of Neutral Rho Mesons", Nuclear Physics B18, 333 (1970). 9. H. Alvensleben et al,!!Photoproduction of Neutral Rho Mesons from Complex Nuclei", Physical Review Letters 24, 786 (1970). 10. H. Alvensleben et al,"Determination of Strong Interaction Nuclear Radii", Physical Review Letters 24, 792 (1970). 11. G. Sanders,"Photoproduction of p0 Mesons on Complex Nuclei", Talk presented at the Herbstschule fur Hochenergiephysik, Maria Laach, Germany, September 1970. 12. H. Alvensleben et al,"p-w Interference in 7iiT Photoproduction", XV International Conference on High Energy Physics, Kiev, September 1970. 13. H. Alvensleben et al,"Photoproduction of Massive Pion Pairs", XV International Conference on High Energy Physics, Kiev, September 1970. 14. H. Alvensleben et al,"Determination of the Photoproduction Phase of p0 Mesons", Physical Review Letters 25, 1377 (1970). -7- 15. H. Alvensleben et al,"Observation of Coherent Interference Pattern Between p-w Decays", Physical Review Letters 25, 1373 (1970). 16. H. Alvensleben et al,"Observation of Coherent Interference Pattern Between p-w Decays", Nuclear Physics B25, 333 (1971). 17. H. Alvensleben et al,"Determination of the Photoproduction Phase of po Mesons", Nuclear Physics B25, 342 (1971). 18. H. Alvensleben et al,"Photoproduction of Pion Pairs With High Invariant Mass", Physical Review Letters 26, 273 (1971). -8- ACKNOWLEDGEMENTS I must first acknowledge my supervisor Professor S. Ting for the example he has set me over the past few years. I have learned from him how research can be pursued in a vigorous and accurate manner. He has provided me with opportunities to test myself and to learn, and with many sleepless nights. He has stacked lead bricks beside me and counseled me and was quick to tell me when I was wrong. To have been his student was a strenuous experience, but one which will, I'm sure, stand me in good stead throughout my career. My colleagues also deserve my thanks. I appreciate the direct help of H. Alvensleben, M. Chen, K.J. Cohen, M. Rohde and H. Schubel. Two in particular, Robin Marshall and Ulrich Becker have my special thanks for the many useful discussions by which they taught me what this experiment was all about. I would also like to thank Wit Busza for discussions of the SLAC experiment, and Jim Trefil for helping me understand the theory. The scientists who made our collaboration possible -9- deserve special mention. They include Professors W. Jentschke, V.F. Weisskopf, P. Demos, A.G. Hill and H. Joos. Interesting comments came from Professors S.D. Drell, B. Margolis, A. Dar, R. Wilson, E. Lohrmann, and others. I thank the people at DESY who always treated me as a guest and provided a photon beam, computer time and auxiliary services in generous quantities. I recall particularly H.O. WUster, D. Lublow, H. Kumpfert and G. Hochweller. DESY is an excellent laboratory. I must not forget those at M.I.T. who tried to make Hamburg and Cambridge seem closer together. They made the repeated ordeal of airplanes and suitcases and shipping crates much easier and kept a steady stream of communication open. The drawing of FraUlein Ingrid Schulz and the typing of Frau Hannelore Feind were indispensable in producing this dissertation. Mrs. K. Ting must be thanked for the skill and effort she put into Fig. 15. Herr Peter Berges' technical assistance must be noted. -10- I would like to thank Hartmut F.W. Sadrozinski for all sorts of things and also because he promised me if I acknowledged him in my thesis, he would acknowledge me in his. I must also express my appreciation for the city of Hamburg (especially the region known as St. Pauli), the continent of Europe, and Alfa Romeos for always providing an alternative to high energy physics. To my parents and family who set me on my feet and gave me a start and always got me from the airport, my warmest thanks. Funds for this work were in part provided from M.I.T. and also from the U.S. Atomic Energy Commission through its contract AT(30-1)-2098 with the Laboratory for Nuclear Science, M.I.T. -11- CONTENTS I. Introduction II. Review of Theoretical Models III. Problems of the Analysis IV. Instrumentation A. The Beam B. The Double-Arm Magnetic Spectrometer C. The Electronics D. The Data-Handling System E. Systematic Effects and Corrections V. Analysis A. Preliminary Steps B. Dynamical Dependencies of the Data C. Model-Dependent Analysis D. Fitting E. Nuclear Radii Determination F. Resonance Parameters, Differential Cross- Sections, Total Cross-Sections and Coupling Constant VI. Comparison With Other Experiments Bibliography Figures -12- I. Introduction The study of high energy phenomena generally involves some sort of scattering process. The internal structure of nuclear matter, interaction dynamics and the properties of the particles used as projectiles or produced in the interaction can be investigated. In the realm of electromagnetic interactions one is particularly interested in the scattering of photons, the quanta of the electromagnetic interaction. The photon and the vector mesons p0 ,w and * have the same quantum numbers J = 1, C = -1, P = -1. This suggests that the study of vector meson scattering may provide information on the nature of photon interactions with nuclear matter. In this thesis I shall describe a detailed examination of the photoproduction of po mesons on a variety of nuclear targets. A simple diagram for this process is shown in Fig. 1. The relationship between the photon and the vector inesons is commonly embodied in the vector-dominance model (VDM)1 . In terms of this model, the incoming photon dissociates into its vector meson components. This dissociation is facilitated by the similarity in quantum numbers, requiring only a -13- mass change in going from the photon to the vector mesons. The decomposition of the photon in terms of the known vector mesons is usually expressed as (1) -j (x) (m2 o/2Y vo) v vP 0,w,- ) (x) v( where j (x) is the total hadronic electromagnetic current, Vo is an index indicating summation over Po ,, and *, mvo is the mass of the respective vector meson, yvo its coupling constant to the photon and v0 (x) its phenomenological field operator. Using this model, the diagram for p0 photoproduction can be drawn as in Fig. 2. Here, the transformation of the photon into the vector meson is depicted as outside the nucleus. The precise question as to whether this transformation occurs before scattering in the nucleus begins or somewhere inside has been discussed by others 2 , with the result that in terms of the vector dominance model, the theoretical results are equivalent. In addition to gaining understanding of the photonvector meson couplingi the study of vector meson photoproduction on nuclei can afford us a way of measuring vector meson-nucleus scattering. Since the vector mesons -14- are short-lived objects one cannot produce beams of them for use in direct scattering experiments. However, using current models3 for scattering inside nuclei, one can interpret the production of vector mesons in the nucleus and their subsequent rescattering in traversing nuclear matter in such a way as to provide information about the vector meson-nucleon scattering amplitude. Since the models for scattering from complex nuclei involve assumptions about nuclear structure (density distributions, radii, etc.) comparison of data on vector meson photoproduction with these models can yield information about these nuclear parameters. That coherent photoproduction takes place without a change in the nucleus' quantum numbers also suggests the process may exhibit an energy and momentum dependence similar to elastic pion and proton diffraction scattering. II. Review of Theoretical Models Since we are dealing with targets consisting of a widely varying number of nuclear constituents, the photoproduction problem is complicated by a whole range of nuclear physics effects. We require a description of the scattering process that takes into account these effects. High energy hadron production is well treated by the Glauber theory' and derivatives of it. Light nuclei can be treated using this model and good nuclear wave functions. Less sophisticated descriptions of the nucleus, when combined with the Glauber theory, provide an adequate description of heavier nuclei. Such nuclei are commonly described by optical models. In the Glauber theory one considers the nucleus to be a collection of discrete scattering centers. An incoming hadron with an impact parameter b and momentum t traverses the nucleus and undergoes a series of scatterings, emerging with momentum t'(see Fig. 3a). In developing the theory a number of physical assumptions -16- are made, and these assumptions define the range of validity of the theory. All momentum transfer to the nucleus is assumed to be transverse. This restricts the theory to scattering at small angles. In the particular case of photoproduction of p0 mesons, this assumption is strictly valid only at infinite energies, since the mass difference between the photon and the vector meson implies that there is some minimum longitudinal momentum transfer. However, even in this instance, parallel assumptions can be made preserving the main features of the theory'. Individual particle-nucleon scatterings are described by phase shifts Xi. It is further assumed that the total phase shift for the complete scattering process off the nucleus is the sum of these individual phase shifts. In optics the analogous assumption (2) XT = Xi would be to consider refraction through a medium as consisting of successive refractions through thin -17- plates of the medium. This requires that successive nucleons be close to each other and lie in each other's shadow. The model also assumes that the incident energy is much greater than the Fermi energy of the nucleons, or conversely, that the interaction time with an individual nucleon is short compared to its relaxation time. Thus the constituents are stationary during the interaction. These assumptions restrict the model to high energy, small angle scattering, implying it is particularly well suited for coherent production. The additive phase shift assumption introduces optical features to the theory. Glauber writes the total scattering amplitude as (3) Ffi() k <ff A id2b{e j 11 2ni where A = - - %', E is the impact parameter, the s are the individual nucleon displacements .from the central axis (see Fig. 3) of the nucleus chosen in the -18- z direction (along t), the Xj are the phase shifts, and the indices f and i refer to the final and initial states. The profile function (the bracketed term containing the phase shifts) is expanded into a series resembling the common multiple scattering series, where each term represents scattering of different order. Thus A A izx×-1 (4) rT = e j = 1- 1[ (1-rk) k=1 A A 3 ) = E rk- E rkr 1 + 0(r k=1 k=1 k l O(r) Note the alternation of signs. The first minus sign has the simple physical interpretation as the effect of nucleons lying in the shadow of other nucleons. Many authors have used the general Glauber theory as a starting point for application to more specific and useful models. These models differ mainly in their assumptions about the nuclear physics. I shall review some of these models, showing the assumptions built into them and make some comparisons with data. +*** -19- In an optical model, Drell and Trefil s have used a simplified eikonal approximation to first calculate the total cross-section, comparing it to pion-nucleon and proton-nucleus cross-sections as a function of A. Assuming the nucleus to be a purely absorbing medium of density p(r) they write (5) Ta = 4r lfb db (1-exp{-U .:p(z,b)dz}) where U is the projectile-nucleon total cross-section 2 2 averaged over protons and neutrons and r = (b +z )1" 2 Using the hard sphere model for the nuclear density (Fig. 3b) (6) p(r) r<roA" 3s {RR(6)0 r<roA'' otherwise and a modified Gaussian distribution (Fig. 3c) (7) p(r) = 1+exp(r 2 -c2 )/ B ; B = (c/2.2)s with s representing the skin depth, they find good agreement with the pion-nucleus and proton-nucleus data if 5N is taken to be 25±10 mb and -NN is -20- 45±5 mb. They also take into account, in the comparison, the change resulting from neglecting the real part of the scattering amplitude. For the coherent po production process, letting A be the momentum transfer, and <f>e i d z be the forward amplitude for po production by a single nucleon at r = (z,b), they write the forward amplitude as (8) fT = 2w<f>•o bdbf'dz exp{- Izop(y,b)dy}p(r)e The integral over p(r) represents the effect of nuclear shape, the term exp..***} is the absorption of p0 mesons produced in the nucleus but absorbed before getting out of it, and the mass change between the photon and p0 is included by the eiAz with Amin = m/2k. They evaluate this expression for the two choices of nuclear density listed above and make a comparison with the early p0 data of ,Lanzerotti et a16 to obtain values for pN' --- --pN albeit large errors, consistent with 30 mb. Finally they indicate the validity of their neglect of the po instability, showing that its mean free path in nuclear matter is much smaller than its decay length. This has also been discussed by Julius' who shows that this -21- is negligible on light nuclei and introduces a maximum error of only 15% on heavier nuclei at the relatively low resonance momentum of 2.7 GeV/c. In a more recent work 2 , Trefil describes a model in which the Glauber multiple scattering series is summed and use is made of the closure approximation to write a single expression which should be valid for all A and in both the coherent and incoherent regions. If one wished to interpret data in which the final nuclear state is known (for example, if one's resolution is such that coherent production can be separated from other processes), then the amplitude can be written (9) F = < oIFI o> where F is the multiple scattering series. A reasonable choice for the ground state wave function To, or Il012 enables ,one to extract information from the data. However, in the more general case of data including events in the quasi-coherent or incoherent regions, all nuclear states contribute, and one can use closure to separate the coherent contribution from all other processes. Thus, writing (10) EIFfil 2 = f 2 = Z<ilFtlf><flFli> I<fIFl i>1 f and applying closure (11) E If><f f - 1 the ground state to ground state transition is isolated. Trefil uses simple nuclear wave functions A (12) p(r) = Iol 2 - 2/2 e-rj/R R22 ; 2 <r j=1 where <r 2>1 ' 2 is the experimental rms nuclear radius. He expects this to obscure some of the nuclear physics, and indeed, in comparing his theory with the 19.3 GeV/c data of Bellettini et al',for proton-nucleus scattering he finds good agreement at low momentum transfer (the coherent diffraction region), good agreement in the incoherent region, but the model fails in the intermediate region where the differential cross-section displays structure. In this region it is sensitive to the details of nuclear shape. The nuclear radius information in the wave function is sufficient to predict the behavior of the cross-section at high and low momentum transfer, even if the shape has been approximated. Trefil also points out that the inclusion of closure is essential for the agreement in the incoherent region, as might be expected. The coherent region is easily treated by Glauber theories or optical absorption models, with or without closure. Trefil also discusses the distortion of the po line shape as a result of the minimum longitudinal momentum transfer, pointing out that this transfer is distributed over the entire nucleus, bringing the nuclear form factor and all other parameters into the problem. In addition, the distortion favors low masses at low momentum transfers, but due to threshold effects, high masses are favored at high momentum transfer, where the nucleon Fermi momentum is small compared to the momentum transfer, and processes like nucleon ejection take place. The analysis of the measurements presented in this thesis was based on a model due to K1lbig and Margolis 8 . These authors sum the Glauber series and use closure to extend the formalism to the incoherent region. This model is intended to treat coherent and incoherent -24- production on medium and heavy nuclei. In performing the summation they have ignored higher order terms in A- 1 and the t-dependence of the particle-nucleon differential cross-section. They treat the problem of the non-vanishing longitudinal momentum transfer (at finite energies). Since the production process is sensitive to the individual nucleon contributions, they present tables of the "effective" number of nucleons involved in the process. The effect of the finite po width (po instability) is not included, although we have already indicated this is a small effect. The formula, as used in this thesis, for the coherent part of the scattering amplitude, includes also the Woods-Saxon density distribution p (see Fig. 3d) as incorporated by Kblbig and Margolis. (13) f= (-0)2 27 fofbdbfoodzJo (b/=te p(z,b)exp(- -I= Q(b) )exp(izvTt_)x . o'(1-ia)/fp~z' ,b)d 2 2 exp(-b 2 /4a)g(z,b)d bdz _0= p 2 (z,b)dz T(b) fp(z,b) 0= dz -25- d(a) = lexp(- OT(b))Q(b)d2b/fexp(- a = 8 (GeV/c) 2 T(b))T(b)d2b s = .545 fm p = po/(1+exp(r-R(A)/s)) This density function gives a more accurate treatment of the nuclear physics effects. Formula (13) includes the modifications to the amplitude due to nuclear correlations as well as its real part. The four unknowns in this equation are: a) fo, the effective forward production amplitude on a nucleus b) 8, the ratio of the real to the imaginary part of the scattering amplitude c) apN, the total p0 -nucleon cross-section d) R(A), the nuclear radius for each A The determination of fo, apN and R(A) can be visualized simply in the following way. For a set of measurements of po production on complex nuclei, the relative normalization determines opN, the absolute normalization determines Ifo 2, and for each nucleus the variation of the production cross-section as a function of momentum transfer determines R(A). mination of 8 later. We will discuss the deter- -26- It is important to note that the value of Ifo1 2 determined from equation (13) should agree with the direct measurement from the process y + p -+ p + p0 . We shall return to equation (13) in our discussion of the analysis. -27- III. Problems of the Analysis Having reviewed some of the models relevant to photoproduction of p0 mesons on complex nuclei, we wish to discuss some of the concepts useful in formulating a method of analysing experimental data. The aim of such an analysis is the extraction 2 of opN, the total po-nucleon cross-section, Ifo 0 , the differential cross-section in the forward direction as a function of A, the shape of the nuclear density distribution, the nuclear radii, and using vector dominance, the photon-po coupling constant y 2 /4r. The problems involved in the analysis of po data are numerous. We are first presented with the uncertainties in the spectral shape. This is generally parametrized by some sort of Breit-Wigner form, but no theory to date can be used confidently for a resonance as wide as the pO. In addition, the shift of the po mass and the skewing of the line shape further complicates the model. In analysing data which includes non-resonant background one must have a scheme for subtracting this portion of the data to -28- isolate the pure p0 contribution. The two most commonly used schemes for calculating the background contribution are both somewhat arbitrary, neither being on a firm theoretical ground. The first, suggested by S6ding 9 , describes the departure from a simple resonance shape as the interference between the pure po amplitude and the amplitude for non-resonant pion pair production in which one member of the p-wave pair scatters diffractively off the nucleus (Fig. 4). The other method involves the use of a term (mP/m )4 to modify the Breit-Wigner shape chosen. Due to Ross and Stodolsky'o this modification then involves fitting the background with an arbitrary function which of course introduces additional uncertainty in the extraction of the cross-section. Nevertheless, both schemes have been used by different groups with success in fitting their data. Julius4 points out some of the problems associated with doing the analysis as a function of A. He comments that from a theoretical point of view, light nuclei are the most suitable for use in determining the po-nucleon interaction parameters. -29- This would be done by studying the dependence of the forward da/d~dm or da/dt on A. However, the contribution from incoherent processes is larger on light nuclei, introducing a large uncertainty in the absolute normalisation. Thus the confrontation between theory and experiment should be made by measurements on heavy nuclei. If one uses heavy nuclei and a model appropriate for high A, such as that of K5lbig and Margolis, one is faced with the extreme sensitivity of the tdependence to the nuclear radius (,R'). Thus, the value of the po-nucleon cross-section depends critically on the set of nuclear radii used. Therefore, in the determination of apN one should study the relative po yields for a set of nuclei, emphasizing higher A, in the region of the pO peak. This minimizes the effects of background, the inability to parametrize the shape of a wide resonance, and normalization uncertainties. The nuclear radii used should ideally be measured at the same time. The vector meson-photon coupling constant can -30- then be determined using (14) 2 2 47r 647r 2 [fo0 from vector dominance. t Another common notation for the coupling constant is gp =P p P 1 P2 -31- IV. Instrumentation A. The Beam The experiment was performed at the DESY 7.5 GeV electron synchrotron. A bremsstrahlung beam of average intensity 1011 equivalent quanta per second and duty factor 2-4% was produced in an internal rotating tungsten target and passed through a series of lead collimators and sweeping magnets. The experimental target was mounted downstream on a calibrated optical bench. The beam spot at the target position was approximately 2x2 cm. and square in shape. The photon beam then passed through a vacuum pipe shielded from the spectrometer by concrete and lead, ending in a Wilson-type quantameter''. The quantameter had a calibration constant of 1.65x10' MeV/Asec and was filled with 90% He and 10% N2. 9 +2% The number of equivalent quanta counted in the quantameter can be calculated from the formula (15) Q = (Quantameter Sweeps) x (Integrator Scale Factor) x 10 x 1.65 x 1019 x (I/kmax) -32- where kma x is the peak photon energy in the bremsstrahlung spectrum. The bremsstrahlung spectrum for the tungsten target can be (16) expressed as f(k,kmax) = T(k,kma x ) a t dk giving the probability a photon has momentum in the range k to k+dk. T(k,kmax) is the spectrum for an infinitesimally thin target i2 and a t is an empirical correction for multiple scattering and absorption in a target of finite thickness. These factors are expressed explicitly as (17) T(k,kmax) = (R-0.925(Z/137) x{ 2 +0.0555)-' (1+(1-v) 2 )x(R-0.91y-0.925(Z/137) 2 ) -(2/3)(1-v)(R-0.1667-0.925(Z/137) at = -(1+30/kmax){0.00082278(1 - v) - 2 -0.647y)} +1.0540 -0.42189v+1 .0953v 2 -0.8049v3 } v = k(kmax+me) Y = 100me Z - 1 3 R = ln(183Z - 1'3 ) (k ma x +me ') - l 1-v) - ' where me is the electron mass. The spectrum is shown(Fig. 5). -33- B. The Double Arm Magnetic Spectrometer Pion pairs produced from pO decay in the target were counted by a double arm symmetric magnetic spectrometer shown in Fig. 6. It consists of dipole magnets (MD, MA, MB), scintillation counters (L2, L3, L4, R2, R3, R4, SLC, SRC), Cerenkov counters (LC, RC, HL, HR) and hodoscopes (TL, TR, QL, QR, VL, VR). The pairs first enter the magnet MD which bends them away from the photon beam and sweeps out low energy background. Pions produced with a central spectrometer momentum po at an angle 8 from the photon beam are bent outwards by 15'-0. Within the effective volume of the magnet (1.0x1.5x0.3 m 3 ), but always at least 5 cm away from the extreme particle trajectories, considerable shielding was placed to reduce the effect of the photon beam line and associated low energy particles as a source of background in the spectrometer. Because of its separation from the extreme particle trajectories the shielding itself was not a source of scattered background. After the MD magnet, the central momentum particles are bent inwards by -8o in the magnet MB (1.029x0.303x0.106 m') which is 2.18 meters downstream from the center of MD. Note that this bending angle is -34- independent of the spectrometer setting (po,Oo) as is the bending of the last magnet MA. This points to one of the spectrometer's properties as listed below. The MA magnets, located 5.39 meters downstream from the MB's, bend the central trajectory particles by -12.930 and have an effective field volume of 1.30x0.488x0.166 m 3 . Three important properties of the spectrometer are: (1) Since the spectrometer setting is changed by adjusting the target position on the optical bench and the MD magnet field in such a way that the bending of the magnets MB and MA are constant, the trajectory of the central momentum particles is nearly identical for all settings. Thus, the spread in position and angle of all particles as they pass through the counters does not depend strongly on the spectrometer setting. Therefore, there is no change in counter efficiencies at different pa and Go. (2) The acceptance of the spectrometer is limited only by the scintillation trigger counters L2, L3, L4, and R2, R3, R4 and not by the magnet apertures or shielding. This eliminates the possibility of accepting particles scattered from the magnet walls or shielding. In order to reduce the rates in the -35- hottest counters so as not to increase corrections for dead-time or decreased efficiency, the counters are placed so that they are not exposed directly to the target. (3) The spectrometer focuses trajectories of constant pem, preserving good mass resolution and large acceptance. Sample acceptance limits are shown in Fig. 7. Typical limits are Ap/po=±0.18, A68/80o-.14, Am/m-+0.10, and A=+±10 mrad, where ý is the projected vertical production angle. In each arm, the two V hodoscope counters, five T hodoscope counters and fifteen Q hodoscope counters, giving 22,500 double arm combinations, provided a resolution in the resonance kinematic quantities of Amp = ±15 MeV/c 2, App = +150 MeV/c, and At = +.001 (GeV/c) 2 . C. The Counters The counters L2, L3, L4, R2, R3, R4 were used as trigger counters. All were tested in an external beam and found to be >99.9% efficient. Made of Pilot Y scintillator, only .3 cm thick to minimize the effects -36- of multiple scattering, they were connected to RCA 7746 phototubes by twisted lucite strips. The tubes were chosen for high gain and low noise and the counters were uniformly efficient over their entire areas, a requirement for fast timing. The dimensions of the trigger counters were L2, R2 (13.47x33.04 cm), L3, R3 (14.91x33.04 cm), and L4, R4 (18.04x43.06 cm). The Cerenkov counters, normally used to provide a veto against pion events during electron runs, were not in the master trigger logic. Since they were physically present, their effects on the measurement (multiple scattering and absorption of pions) were included in the corrections to the data. Scalers recording the coincidence rates between the Cerenkov counters and the pion trigger indicated the electron contamination of the data was always less than 1 part in 10 4 , as might be expected. D. The Electronics The logic, shown in Fig. 8, consisted of circuits capable of operating at 160 MHz, minimizing dead-time and accidental coincidences. The resolving times and -37- pulse widths of each circuit are indicated in the diagram. In each arm, a coincidence was formed between the trigger counters L2,L3,L4 and R2,R3,R4 (the counters SLC and SRC were inserted in coincidence with L2 and R2 to reduce the singles rates in these counters). The two arms were then put in coincidence forming the circuit AX. AX was then put in coincidence separately with each of the three pairs of trigger counters (L2,R2; L3,R3; L4,R4) forming Xl, X2, and X3. The triple coincidence of these three circuits formed the master trigger MT. Thus the coincidence AX provided a preliminary indication of an event and was used as a gate to open the more stringent logic network X1, X2, and X3, the coincidence MT being the final indication of a double arm coincidence. Up ,to this point, the Cerenkov counters have not been inserted into the logic. Two of the Cerenkov counters (LC, RC) were not used in this experiment. From the diagram it can be seen that coincident pulses from the two Cerenkov counters HL and HR were used to signal that electrons have passed through the arms. -38- The electron flag MP was formed by logic similar to the master trigger logic. The preliminary coincidence AP was used to gate the final network forming MP. Events in which an electron was indicated in one arm fired the circuit MK, and they constituted less than 5% of the data. All events which satisfied the MT trigger were recorded. The final choice to discard events with MP or MK on was made later in the production of the data library tape to be described. Accidental coincidences were monitored by parallel logic networks with different coincidence resolution times. Correction for this effect could then be made later by extrapolating the rates for the different coincidence widths T to T = 0. This will be mentioned again in our discussion of systematic corrections. At all times, however, this correction was kept below 2%. E. The Data Handling System For each event, pulses from the hodoscope counters, the master trigger pulse MT and the electron pulses MP and MK were read into a matrix of gated latches. A PDP-8 computer was triggered by the MT signal, and under -39- program control, scanned the latch matrix. This information was decoded by the computer which then did the following things: (1) Produced a display of all events in the run showing their distribution in the hodoscopes. This display was useful in checking for counters which failed to operate or whose efficiency had fallen because of some equipment failure. (2) Separated events which were characterized by one hodoscope bank failing to record the event, possibly due to some inefficiency, or in which two or more counters in one bank fired, possibly a random coincidence. These events could not be sorted into kinematical distributions, but since they had satisfied the trigger requirements, they contributed to the total normalization. Both categories of events totaled between 5% and 10% of the counting rate. (3) Wrote the events on magnetic tape in undecoded form. Each event consisted of 16 six bit words, including the hodoscope information, special latches, the run number and event count in BCD format. This format is shown in Fig. 9. (4) Transmitted the events to an IBM 360/75 which ran on-line. This on-line system performed a number of tasks. A block diagram of the system is shown in Fig. 10. -40- Events received by the 360 were binned in resonance m, p, and t, and divided by the spectrometer acceptances and other relevant quantities, providing cross-sections which were sent back to the PDP-8 for immediate display. The results of previous runs were saved on disk data sets and combined spectra could also be commanded from the PDP-8. All data could be dumped onto magnetic tape for further analysis. (5) Printed out all run parameters, event plots and cross-sections at the end of each run. F. Systematic Effects and Corrections During the experimental runs all systematic effects were monitored, and the information obtained was used later to make corrections to the data. Data was taken at both spectrometer polarities to insure that the spectrometer was indeed symmetric. The agreement of the two rates confirmed this symmetry. The voltages on all counters were kept constant to within ±5 volts and all magnetic fields were held stable to within 3 parts in 10 . -41- Normalization runs were made every few hours, and the reproducibility of the rates measured in these runs was better than ±1% at all times. All data were taken with the resonance p close to the maximum photon energy kmax (kmax/p1l. 2 ) so as to minimize inelastic contributions. The targets were chosen with purity greater than 99.9%. The thicknesses of the targets were chosen to keep the corrections for beam absorption and pion absorption uniform, and to give yields much greater than the target-out rater Fig. 11 is a table containing information on the targets used in the experiment. Additional systematic effects were treated as normalization corrections. The corrections were all made to the number of quantameter sweeps (equivalent quanta of the photon beam) recorded in each run. The correction formula used was (18) QM corr= QM GM MT rawx---x-x(1-DT)x UGM X1 1 x(1-NA)x -1- 1-BL RA -42- We shall discuss each of the terms in this expression, corresponding to each individual correction to the raw quantameter sweeps (QMraw) needed to get the corrected sweeps (QMcorr). (a) Due to the structure in time of the synchrotron spill, the electronics were gated on only during the central, useful portion of the beam pulse, by gating signals from the synchrotron. However, the quantameter, a slow device, could not be gated. Two monitor circuits, one gated (GM) and the other on at all times (UGM) were used to correct for the additional quanta recorded during periods when the gate was off. Typically, this correction was 2-3%. (b) When an event was recorded by the latch matrix, a new could not be recorded until the PDP-8 computer completed its scanning sequence. During this time, a busy-anti signal held the electronics inactive. The circuit MT, previously described, was controlled by this signal, the coincidence X1 was not. The ratio of the rates in these circuits provides an accurate correction for this effect, typically less than 4%. (c) The dead-time (DT) correction was done in the following way. Noting that (19) DT = (rate)(resolving time) (duty factor) -43- the resolving time of the circuits, already described as 160 MHz circuits, was multiplied by the rates in the hottest counters L2 and R2. These rates were measured every half hour during the runs and the synchrotron intensity was regulated by these measurements, so as to control the dead-time correction. The rates were then averaged over the runs and used in this calculation. The duty factor is a function of the synchrotron beam structure, and is used to convert the average rates in L2 and R2 into instantaneous rates. Using a triangle approximation for the pulse shape, and noting that the synchrotron ring was only partially filled (this filling factor is a function of the machine energy, intensity and the skill of the operators) formula (19) can be rewritten as (20) DT = (L2/R2 rate)(1/160x106) x(1/(fill factorx2x50xspill width(sec)x2.75)) where the constant 50 comes from the 50 pulses per second, 2.75 is an empirical correction due to clipping, 2 comes from the triangle approximation and a typical spill width is 5x10-4 seconds. Dead-time corrections were ,2%. -44- (d) A portion of the photon beam was absorbed in the target before it could be recorded in the quantameter. This beam loss (BL) correction was calculated using formulas for photon absorption from Fermi'3 (21) n no = e o(cm2 = Z2 137 28 e 183 9 Z 3 2 27 This is based on the assumption that most of the photon absorption is due to pair production, valid for 7 GeV photons. Comparison with more recent calculations of T.M. Knasel'4 showed excellent agreement. In addition, a series of special runs were made with target thicknesses of carbon ranging from 0 to 5 gm/cm 2 tO check the sensitivity of the count rate to second order effects, in beam loss and pion absorption. The rate was linear within 1%, and is shown in Fig. 12. (e) Absorption of pions in the target and in the spectrometer material (nuclear absorption NA) was treated by a combination of measurements and theoretical calculations. Cross-sections for elastic scattering and absorption of '+ and r- mesons on Beryllium, Carbon, Aluminum, Copper were taken from Longo and Moyer's, Values for other elements were obtained by interpolation (see Fig. 13). These cross-sections were used to calculate -45- the pion loss in the targets and in the spectrometer. The assumption was made that the total cross-section (absorption and elastic) accounted for the loss before the last magnet MA since elastically scattered particles would be swept out by the magnetic field. After the MA, particles scattered elastically through small angles would still be accepted, so only the absorption crosssection was used. The use of the Longo and Moyer cross-sections and the assumptions mentioned was checked by varying the amount of material in the spectrometer. This was done by changing the gas pressure in the Cerenkov counters, both for the counters before the MA magnets, and the pair after the MA's. The measured change in the rate was in good agreement with the calculated values. The corrections for pion absorption for the spectrometer and each of the targets is listed in Fig. 11. (f) Accidental or random coincidences (RA) were monitored during the experimental runs by a series of parallel logic networks with different coincidence widths, already described. The rates in the circuit AXW (15.3 nanoseconds resolution) and AX (5.9 nanoseconds resolution) were then extrapolated to zero resolution time, this rate being considered the true -46- rate. During the runs, the synchrotron intensity was controlled to keep the accidental rate less than 2% of the total rate. An additional precaution taken to minimize systematic corrections was the use of helium bags at all places possible along the spectrometer. This minimized the target-out contribution. Target-out runs were taken for each setting of the spectrometer and the measured rates were subtracted from the target-in rates for the various targets. -47- V. Analysis A. Preliminary Steps Events written on magnetic tape by the on-line IBM 360, in the format shown in Fig. 9, were decoded by an off-line program. Events for each run were grouped into a matrix of dimension 22,500 = 2x5x15x2x5x15 corresponding to the hodoscope combinations. The matrix, plus all important run parameters (run number, spectrometer setting, synchrotron energy, quantameter sweeps, etc.) were then written onto a data library tape. This tape contained such a block of information for each of the 278 data runs, ordered according to target, resonance momentum, and spectrometer angle, so as to facilitate the analysis. This tape was then used to sort all the events for a given 'central resonance momentum (4.5, 6.0 and 6.7 GeV/c) into a 4-dimensional matrix (A,m,p,t ) of dimension (13,20,10,20). The 20 intervals in dipion mass spanned a range of 400-1000 MeV/c 2 , -the 10 momentum intervals covered 3.5 to 7 GeV/c, and the 20 transverse momentum transfer intervals went from 0.0 to -0.04 (GeV/c) 2 -48- The high statistics of the experiment (more than one million events), the use of the large number of elements and the organisation of the data into a matrix of kinematic quantities enabled careful study of the dependencies of the data on each of the individual dynamical quantities. Variation of the cross-sections on m, p, t_, and A could easily be isolated and the effects of cuts in these quantities could be studied. The kinematic assignment of the events to this matrix was done using Monte-Carlo generated assignments. Events were generated in the target, and transported through the spectrometer. Magnet transport was done using fourth-order magnet transport equations. Tests for accepted events were made at all magnet apertures and trigger counters. The transport included the effects of multiple scattering in the target and along the spectrometer, since this phenomenon smears the resolution of kinematic quantities. Since the spectrometer was symmetric, the simulation was done only for pions traveling along one arm and the generation of the pions in the target was flat in momentum and polar angles. Accepted events were binned in -49- hodoscope combinations, producing an assignment of <p>, <e>, and <ý> for each single arm hodoscope combination. This single arm simulation was extremely fast on the computer, enabling very good statistical accuracy of the assignments. The pion pairs for each experimental event were then assigned a p, 6, and ý for each member of the pair and the kinematical quantities of the dipion system could be calculated. The events were then binned in the data matrix. Correction by the spectrometer acceptance factor was required to extract cross-sections d 2a/dadm from the data matrix. These acceptances were also calculated by a Monte-Carlo technique, using a transport which included both arms of the spectrometer, pO mesons were generated within the target, allowed to decay, and the decay pions were transported through the two spectrometer arms. The transport, like the single arm program, included the effects of multiple scattering, but in addition, simulated the decay of pions in flight. This Monte-Carlo program produced an acceptance -50- factor for each hodoscope combination, as well as for the entire spectrometer window. For pO production with a differential cross-section d2a/ddm, the counts in a given (22) hodoscope combination is given by d2o f(k,km....) W(s2') d2d2'dmdk dmdk f(kkdk N = Nt Qeff fhod dodm dSdm k 4Tr where N is the number of events, Nt the number of target particles per cm 2 , Qeff the effective quanta (formula 15), f(k,kmax) is the weighting due to the bremsstrahlung spectrum (formula 16), W(0') is the p0 decay angular distribution in the c.m. system, and "hod" designates an integral over the phase volume of one hodoscope combination. This integral can be performed over the whole spectrometer window as well. Inserting a factor to transform the integral to one over dp (not dk) and assuming the variation of d2a/d2dm(m,p,t) to be small over a single hodoscope combination we can rewrite (22) (23) N = Nt Qeff f(kk_ k hod (k d2dm W(') ddn'dmdp dd2'dmdp pk 4Tr The integral portion of this expression is the unweighted acceptance of the combination "hod", and can be written in the usual Monte-Carlo prescription -51N (24) ACChod I ( Ntrial x if succ f k CCf(k = Tr ka) ki AmnpAna - Piki ' 47r where N is the number of Monte-Carlo successes, and Ntrial is the number of Monte-Carlo trials. The sum is performed for each event which succeeds in surviving the transport. A sufficient number of Monte-Carlo successes was generated at each spectrometer setting to reduce the effect of statistics far below the experimental statistics. The 4-dimensional matrix of data was then constructed in the following way. After each event was assigned a bin in the space of A, m, p, and t_, it was divided by Nt and Qeff to produce a count rate, and further divided by ACChod to yield dz2/dadm(A,m,p,t_). This simplified procedure, however, ignored the effect of the spectrometer's finite resolution. An event observed in a given hodoscope combination, and assigned an m, p, and t_ on the basis of that combination may actually have a different m, p, tl, within the spectrometer resolution. This can have an appreciable effect on d2 0/dadm particularly at the edge bins of m, p, and tl. -52- For example, for infinite statistics and perfect resolution, a plot of the cross-section as a function of t in the coherent diffraction region might be expected to look like Fig. 14 where tmin is the minimum momentum transfer possible. The effect of spectrometer resolution could smear this shape in a manner shown by the dotted, so that some events would be assigned t values below the physical limit. To minimize the effect of this smearing on the fitting to be applied later, a correction must be applied. The procedure used necessitated assuming a production mechanism and weighting the acceptances. Previous experimental measurements 26 show that, above 2.7 GeV/c, the form (25) d2a = p 2 2mR(m)f (t) d2dm can be used. This procedure assumes all events are from coherent production and the function fc (t) used was from the, paper of K1lbig and Margolis' discussed previously. The mass dependence is a Breit-Wigner form. As each Monte-Carlo event was generated, it could be assigned an mo, po, and to from its generated kinematic parameters. A second set of mh, Ph, and th was assigned on the basis of the hodoscope combination it was "observed" -53- in, the assignment being made on the basis of the single arm quantities described previously, in a manner analogous to the experimental events. The weighted acceptances were then calculated according to N (26) 1 WACChod = ( Ntrial x succf(k sE i=1 k i m.) ki Tr Poik i W(__i i 47T pi2moiRi(mi )fc. (toi)) AAQ'AmAp which is similar to formula (24). The procedure for construction of the matrix of d2 a/dQdm(A,m,p,t,) was then modified by using the following expression instead of (23) (27) d'o (A,m,p,t 1 d2dm ) = N f (A,m,p,t,) NNNtQeffWACC Comparing this procedure with the one using unweighted acceptances showed no effect except at the edge bins where the distortion due to resolution was effectively removed, indicating the production mechanism chosen was essentially divided out and would not affect later fitting attempts. -54- B. Dynamical Dependencies of the Data The 4-dimensional data matrix comprises a comprehensive collection of the results of this experiment. With it, all the dynamical dependencies of the data are revealed, and the cross-sections it represents are the measured quantities, independent of any assumptions of models, production mechanisms and background contributions. A given slice of the data, for a particular resonance m, p, and t_ as a function of A, illustrates the major physical processes measured. For example, choosing p = 6.2+0.2 GeV/c, the cross-sections are plotted versus m and t1 for all the nuclei in Fig. 15. The po resonance is clearly observed. The t-dependence illustrates the diffraction production on nuclei. The contribution of non-resonant background can be seen from the variation of the mass spectral shapes as a function of A and t1. A clearer illustration of the dependence of this background on A can be seen in Fig. 16 where the spectra for three elements at resonance <p> = 6.0 GeV/c has been divided by the -55- p and t_± dependence isolating the mass dependence. In the absence of background, the spectra should be identical. Note the difference on the low mass side of the resonance peak. In addition, the less rapid fall-off of the spectra below the central mass indicates the skewing of the resonance shape. At this point, no significant physical assumptions have been introduced in the presentation of the data and the portion of the cross-section matrix shown in Fig. 17 represents the measurement in a pure form. Further analysis requires the use of theoretical models. C. Model-Dependent Analysis The data matrix was then fit to a function of the form (A,m,p,tl (28) = 2 mRn(m)p 2 (fc+finc) + BG(A,m,p,tJ) dQdm where the first term represents the resonant contribution and the second term is the non-resonant background. Rn(m) is a parametrization of the mass shape, fc is the coherent production cross-section as a function of A, -56- t , t.L, opN' R(A), and B, the ratio of the real to the imaginary part of the forward scattering amplitude on a single nucleon. finc represents the analogous contribution from incoherent processes. The coherent contribution was calculated using the model of K61big and Margolis 8 . We have already written the expression for this contribution in formula (13) with the Woods-Saxon nuclear density. Ifo1 2 is the forward differential cross-section on a single nucleon. The attenuation of nuclear matter is represented by exp(-(a'/2)fzpdz). The effect of nuclear shape is given by p(z,b)Jo(bVT!T7, and the mass change between the photon and the p0 gives the factor exp(iz/ T). The model of Von Bochmann et al '6 was used to incorporate the effect of nuclear correlations in this expression, resulting in a modification of the po-nucleon cross-section. The new quantity a' includes 5, the correlation length, and g(b,z), the correlation wave function. The ratio of the real and imaginary parts of the single nucleon scattering amplitude is 8. A measurement -57- of yp total cross-sections up to 6.0 GeV1 7 gives ý = -0.2, consistent with a determination made in the measurement of the interference between po+e e pairs"s . and Bethe-Heitler The value of B = -0.2 was used in this analysis. Incoherent contributions were treated according to the prescription of Trefil' 9 and the background was fit with a general polynomial in A, m, p, ti. Because of the uncertainty in parametrizing the mass distribution of a wide resonance, several forms were used in the analysis. If (29) r(m,F(m)) = r(m) = mpr (m) 1 r (m2 -m2 ) 2 +m2 r 2(m) p P is the relativistic p-wave Breit-Wigner shape due to Jackson 2 0 , the various forms used were (30) Ri(m) = r(m) (m /m) R2(m) = r(m) + I(m) Ra(m) = r(m) (mp/m) + I(m) R4 (m) = ro(m) = r(m,fo) Rs(m) = r(m) -58- where m2 (31) I(m) = D m (m2 -m 2 ) 2 +m2 P P 2 (m) comes from the Siding interference mechanism 9 , and (32) F(m) (m/2-m m is (m /2)2 p 2 7T a mass-dependent form of the width of the resonance peak. The factor (m /m) 4 is the Ross-Stodolsky factor 1 0 . This factor has also appeared in a model by Kramer and Uretsky 2 1. D. Fitting The fitting was done with the CERN program MINUIT 2 2 . In order to reduce the contribution of background and incoherent processes, the data was restricted to the kinematic region dominated by coherent pO production. This was done by making the cuts Itl<Itcl , t GeV 2 /c2 ; 4.8 GeV/c <p< 7.2 GeV/c; and m>mc, = -0.01 mc = 600 MeV/c 2 . The sensitivity of the fitting to these cuts was studied. The results were insensitive to changes of mc by +100 MeV/c2 or tc by 0.01 (GeV/c)2 . -59- Similarly it was found that the background function (33) BG(A,m,p,t) 1 = ( E ai(A)m)( i=O m Z b (A)pl)( j=o j n k Z Ck(A)t) k=O could be restricted to 1=2, m=n=O since the fits did not improve for higher orders. E. Nuclear Radii Determination By fitting the data as a function of t with equation (28) a determination of the nuclear radii R(A) for strong interactions was made. Previously, nuclear density information had been taken from electron23or proton24 scattering on complex nuclei involving the assumption that the densities for electromagnetic and strong interactions are equivalent or ignoring the Coulomb interaction of the proton. A determination from po mesons is free of either complication. In addition to the restrictions placed on the data above, separate fits were made to the t1 -dependence of each of the six mass intervals between 690 and 870 MeV/c2 . This was done to minimize the sensitivity of the radii determination to the parametrization of the -60- mass dependence. Fig. 18 lists the results of these fits in the first six rows. The background function was assumed to be zero. For the heavier elements (A>27), the six radii agree with each other indicating the non-resonant background is very small or is produced diffractively. The lighter elements Be, C and Al do not show such consistency, the radii varying from one mass bin to another. This indicates that despite the restrictions made to the data, there is a considerable contribution from background. To further study the effect of background, fits were made with various explicit assumptions. For example: (a) Background independent of p and t,, (b) Background BG(A,m,p,tL) dependent on p and tL bin, (c) Background a smooth function BG(A,m) represented by a power series in m and all mass bins fit simultaneously with Ri(m) as in equation (30), (d) Background a smooth function BG(A,m) with the distribution R2 (m) used. Rows 8, 9, 10, and 11 of Fig. 18 list the results of these fits. For A>27, these fits and those made with the choice of no background are consistent. Row 12 of Fig. 18 lists the best values for the -61- radii, these being weighted averages of the individual mass bins. Fig. 19 shows these values and the fit to the scaling law (34) 3 R(A) = roAA' The individual fits to this law are also listed in Fig. 18, as are the rms radii corresponding to the best values of R(A), calculated according to25 (35) R2 rms = 0.6R2 + 1.4s 2 The errors in this calculation range from 2% on heavy nuclei to 10% on lighter elements. This can be attributed to the increased sensitivity to the background and the skin thickness for A<27. In addition, the model of K61lbig and Margolis is better for higher A. The fitted rms radii are insensitive to the skin thicknes's parameter s, this having been checked by fitting with s = 0.5 fm and s = 0.6 fm and noting no significant effect, independent of A. -62- F. Resonance Parameters, Differential CrossSections, Total Cross-Sections And Coupling Constant For fixed A, p, tl, the data was fit to equation (28) to determine the mass and width of the resonance. Independent of the mass parametrization used, the width was (36) 0o = 140 + 5 MeV/c 2 The results for the resonance mass are shown in Fig. 20 for each mass distribution, and the best value determined from fits with Ri(m), R2 (m), and R3 (m) is (37) m = 765 + 10 MeV/c2 Inserting the values for R(A), m p,0 and BG, the data was fit for the coherent differential cross-section do/dt(A) t=O. Values for such cross-sections for 6=O0 Itl=0.002,p=6.54,kmax= 7 .4, are tabulated in Fig. 20, with the errors. The index n on these En's corresponds to the various mass forms described. The errors include the uncertainties in R(A), mp, To, and the background. Fig. 20 also lists values for the ratio of chi-squared -63- to degrees of freedom X2 (A)/DF(A) for these fits. Ri (m), R2(m), R3 (m) give better fits than the other hypotheses. The fits for R 1 (m) are shown as the curves in Fig. 15 as well as in Fig. 21 where the background contribution is also shown. The background per nucleon is independent of A, indicating it is predominantly incoherent. The A-dependence of the El cross-sections is shown in Fig. 22. Using the measured radii R(A) and the value 6=-0.02, fits were made for apN , If 0 12, and using (14), y 2 /47r pN p The results are also tabulated in Fig. 20 and the values are consistent from one mass hypotheses to another. Choosing the values corresponding to ZC (38) apN = 26.7 + 2.0 mb Ifo 0 2 = 118 + 6 pb/(GeV/c) 2 Y 2 /41 = 0.57 + 0.10 Checks made on the fitting procedure included the successive elimination of the light elements Be, C and Al. The insensitivity of the results to this procedure indicated the heavy elements dominated the analysis, consistent with the use of the model of Kl1big and Margolis. In addition, application of more restrictive cuts in m, p, and t_ did not significantly effect the results. Changing 8 by ±50% led to only a 10% change in y2/4w and less than 1% change in the radii R(A). Finally, apN changes by only 1 mb for a 5% variation of R(A). -65- VI. Comparison With Other Experiments The study of photoproduced po mesons on complex nuclei has been a controversial field. At times there have been dramatic disagreements between various experimental groups. The experiment described in this thesis was motivated by a desire to resolve the discrepancies. The complications of treating nuclear physics effects, parametrizing the resonance line shape and subtracting non-resonant contributions have been major sources of controversy. Therefore, in this experiment, the analysis was as general as possible, including several alternate hypotheses. The situation is now somewhat improved, due to the experiment reported here, other recent experimental efforts, and a substantial amount of communication between the various groups involved. Fig. 23 is a table listing the various experiments we wish to compare. The experimental conditions, results, and any special factors in the analysis are shown. The early experiment of Asbury et a126 was analyzed -66- using simpler nuclear models, specifically, the prescription of Drell and Trefil s with a hard sphere density. No provision was made to include the effect of nuclear correlations, or the real part of the scattering amplitude. A subsequent analysis of this data by Margolis 2 7 using a Woods-Saxon density and including ý gave a number for apN slightly lower than the original result. The most recent analysis of the data of McClellan et a128 gives results which agree well with those reported in this thesis. Previous disagreements can be attributed to assumptions made in the analysis, such as the failure to include B. Background was treated using the Siding interference' and no other contribution. As in all the current experiments, the model of Kblbig and Margolis was used for the coherent amplitude with a Woods-Saxon density. Two sets of nuclear density parameters were employed, one from their own "best-fits" with an optical model, and one set from electron-scattering data (Hofstadter data). The results are shown in the figure. Data from SLAC (Bulos et a1 2 9) gives a opN in -67- agreement with other efforts. However, the coupling constant y2 /4w is somewhat high. This can be attributed to differences in this group's data. The higher coupling constant comes from their cross-sections which are about 30% lower. In addition, analysis of their complex nuclei data alone gives da/dt(yp) t=0- 7 5 pb/(GeV/c) 2 . Further analysis is being carried out. Finally, an experiment by a group from Rochester, Behrend et a130 was carried out on the Cornell synchrotron. This group used a Ross-Stodolsky1 o modified Breit-Wigner and the Kilbig-Margolis model. Nuclear densities chosen were Woods-Saxon forms, but for the lighter targets Be and C they employed harmonic wells. They used B= -0.02 but did not include nuclear correlations. They were able to fit their data for da/dt(yp) t.0 but preferred to extrapolate the number quoted in this thesis to their energy region. The results obtained;, as can be seen from Fig. 23, are consistent with this paper. The situation to date is that the experimentalist is capable of measuring the photoproduced po spectrum on nuclei to a precision where superior theoretical models are required for their exact understanding. -68- BIBLIOGRAPHY 1. N.M. Kroll, T.D. Lee and B. Zumino, Physical Review 157 (5), 1376 (1967). 2. 3. J.S. Trefil, Physical Review 180 (5), 1366 (1969). J.S. Trefil, Physical Review 180 (5), 1379 (1969). R.J. Glauber, in Lectures in Theoretical Physics, (Wiley-Interscience, Inc., New York, 1959), Vol. I, page 315. 4. D. Julius, thesis, Cornell University, 1969. 5. S.D. Drell and J.S. Trefil, Physical Review Letters 16, 552 (1966). 6. L.J. Lanzerotti et al, Physical Review 166 (5), 1365 (1968). 7. G. Bellettini et al, Nuclear Physics 79, 609 (1966). 8. K.S. Kilbig and B. Margolis, Nuclear Physics B6, 85 (1968). 9. P. Siding, Physics Letters 19, 702 (1966). 10. M. Ross and L. Stodolsky, Physical Review 149, 1172 (1966). 11. R.R. Wilson, Nuclear Instruments 1, 101 (1957). F. Peters and E. Raquet, DESY Internal Report 52-69/1, 1969. -69- 12. H.W. Koch and J.W. Motz, Reviews of Modern Physics 31, 13. 920 (1959). E. Fermi, Nuclear Physics, (University of Chicago Press, Chicago, 1950). 14. T.M. Knasel, DESY Report 69/8, 1969. 15. J.M. Longo and B.J. Moyer, Physical Review 125, 701 (1962). 16. G. von Bochmann, B. Margolis and C.L. Tang, Physics Letters 30B, 254 (1969). 17. J. Weber, thesis, DESY, 1969. 18. Ii.Alvensleben et al, Physical Review Letters 25, 1377 (1970). 19. J.S. Trefil, Nuclear Physics 20. J.D. Jackson, Nuovo Cimento 34, 1644 (1964). 21. G. Kramer and J.L. Uretsky, Physical Review 181, 1311, 330 (1969). 1918 (1969). 22. F. James and M. Roos, CERN 6600 Computer Program Library Write-Up D 506. 23. H.R. Collard, L.R.B. Elton and R. Hofstadter, in Landolt-Boernstein Tables, (Springer Verlag, Berlin, 1967), New Science Group I, Vol. 2. 24. R.J. Glauber and G. Matthiae, ISS 67/16. 25. P.E. Hodgson, The Optical Model of Elastic Scattering, (Oxford University Press, Oxford, 1963). -70- 26. J.G. Asbury et al, Physical Review Letters 19, 865 (1967). 27. B. Margolis, Physics Letters 26B, 524 (1968). 28. G. McClellan et al, Report submitted to the XV International Conference on High Energy Physics, Kiev, 1970. 29. F. Bulos et al, Physical Review Letters 22, 490 (1969). R. Larsen, Private communication. 30. H.J. Behrend et al, Physical Review Letters 24, 336 (1970). -71- FIGURE CAPTIONS Fig. 1 Feynman diagram for photoproduction and decay of p0 mesons on complex nuclei. Fig. 2 Feynman diagram for photoproduction and decay of p0 mesons on complex nuclei showing intermediate virtual pO propagator from vector dominance model. Fig. 3 a) Schematic diagram of scattering problem treated by Glauber theory. b) Hard-shell nuclear density. c) Modified Gaussian nuclear density. d) Woods-Saxon nuclear density. Fig. 4 S3ding mechanism Fig. 5 Bremsstrahlung spectral functions. Fig. The symmetric double-arm magnetic spectrometer. 6 Feynman diagram. Fig. 7 Sample spectrometer acceptance window. Fig. 8 Schematic diagram of trigger logic. Fig. 9 Data tape format. Fig. 10 On-line data handling system. Fig. 11 Information about the experimental targets including absorption of the photon beam in the targets and absorption of decay pions in the targets and along the spectrometer. -72- Fig. 12 Pion pair yield as a function of carbon target thickness. Fig. 13 Plots of pion absorption and elastic scattering cross-sections taken from Longo and Moyer. A linear interpolation was done to extract crosssections used in correcting data. Fig. 14 Sketch showing smearing of t-dependence of do/dt due to spectrometer resolution. Fig. 15 For <p> = 6.2+0.2 GeV/c the differential cross-sections are displayed as a function of A., m, p, Fig. 16 tl. Curves are fits (see text), Mass spectra for three elements after removal of p and t dependence showing presence of non-resonant contribution. <p>= 6.0 GeV/c. Fig. 17 Production differential cross-sections for all elements in a selected m, p, t_region. Fig. 18 Summary of nuclear radii. Fig. 19 Best values for R(A) and fit to R(A) = roA /3 Fig. 20 Summary of results of fits for nuclear radii, differential cross-sections, apN' resonance parameters and y-p coupling constant. Fig. 21 Result of Zi fits for p = 6.2 GeV/c, all elements. Incoherent background is shown. -73- Fig. 22 A-dependence of d dt Fig. Comparison of various pO experiments. 23 =0(A). - 74- Fig.1 /11. / --- C---Tv Fig. 2 / a Ti'[ / A ------it P PF -75- I- 0L aa C) 1.L. L0 ti o d €• .. Cf j •CL Q. . -76- /TL A A A iT0 0 Fig.4 -77- r E E Tra X E E Ne '4- C0, I aC CU, co LO LL -78 - c-f +n +r +t (0 01 Go3 or -79- NI I I -80- aJ w 6) Li - T 0 LAI -81- 1 I 1 I ttt~tI ADC OUTPUTS T T 14 3 1' 2 QR15 QR14 QR13 QR12 QR11 QR10 I QR9 QR8 QR7 QR6 QR5 QR4 C, ) QR3 QR2 QR1 QL15 QL14 QL13 QL8 ) QL12 QL11 QL10 WORDS IQLsIQLsIQLliL..IL3L2IQL1 I QL6 LS QL4 QL3 OL2 QL1 ITRSI TR4 ITR 3I TR 21 TRi IQL9 I IA I T-1--" I TL5 I TL4 I TL3 I TL2 I TL1 I MP I -+--I T-{vI M I TAPE JI MKSIL1QL7 1 MK ] I SI 1~ IA Ii I 2 RUN NUMBER 4-I8-11 21 (BCD FORMAT) I 14 8 EVENT NUMBER (BCD FORMAT) 1 ' 8 I I 1 2 2 14 8 · I' I t1I21LIR81112I1 VII 1 I L 3 4 5 TRACKS PDP - 8 DEC TAPE Fig. 9 0 / DIRECTION -82- LLI < cn C, .J z uI 0 -83- TARGETS ELEMENT THICKNESS pT BEAM LOSS TE-ABSORP. Z A (cm) Be 4 9.01 1.5 2.85 1.6 6.87 C 6 12.01 1.5 2.52 2.3 4.11 Al 13 26.98 .5 1.36 2.2 2.13 Ti 22 47.90 .2 .897 2.1 1.31 Cu 29 63.541 .1 .910 2.8 1.22 Ag 47 107.9 .1 1.06 4.6 1.42 Cd 48 112.4 .07 .585 2.5 In 49 114.8 .12 .792 3.5 1.07 Ta 73 180.9 .06 5.8 1.36 Ta 73 180.9 .04 .694 3.8 .91 W 74 183.9 .02 .422 2.4 .56 Au 79 197.0 .02 .452 2.7 .59 Pb 82 207.2 .05 .522 3.1 .68 U 92 238.1 .025 .602 3.9 .78 (g/cm) 1.04 i: - ABSORITION IN SPECTROMETER IS 13.3% Fig. 11 (%/) (%) .79 -84- RELATIVE YIELD 300 E 7 200- 100- -i - / II i- THICKNESS OF CARBON TARGET ·3 r I- 1cm. I 2cm. Fig.12 I 3cm. -85- 0 (mb) 1000- +o (TCiL) 4 o (TEs) 4 0( t;BS) 100 Be S-I- _ ____1 4 . C 4 · A 1 · Fig.13 · · rr·· · I | · I -86- L zIZ 2l 01 -87- LL. LL -88- 2 2 o0 f--o- -+- >•Y •E + / WOO 0o c-- i U_ \ '.. \--4 II i m l I -4-n ' " I " I . . . . ' \ \ i 6 a, \U* -4- - ~'-a. - \ -891 •"r BERYLLIUM -T = I in I 0.001 pb/sr.MeV/c Z vs. m(MeV/cZ),p(GeV/c) and t, (GeV/c)2 I 0.003 m 1 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 I 1005 P_-= I 11.3 1 11.0 I 12.0 I 12.9 | 16.1 I 17.0 I 21.8 1 30.6 I 36.1 I 32.1 I 20.2 I 12.1 I 9.0 I 5.2 I 1.7 I 1.7 ± + ± ± + + ± + + ± + . ± + + ± 2.2 1.8 1.7 1.6 1.3 1.4 1.5 1.5 1.5 1.8 1.8 1.4 1.3 1.2 0.8 0.8 0.5 + 0.6 1 1.1 + 495 1 525 1 555 1 585 I 615 1 645 1 675.1 705 1 735 I 765 I 795 I 825 1 855 1 885 I 915 I 945 I 975 1 1005 I 8,sGEVC I 0.007 0.009 . 6.1 5.4 14.6 15.2 5.6 7.8 11.7 19.0 29.9 19.9 16.7 4.0 4.9 3.6 12.4 1.2 + + ± + + + ± + + + + ± ± ± ± 5.2 2.5 4.6 4.7 2.8 3.5 2.7 3.1 3.0 3.3 5.7 2.1 2.6 2.6 5.6 1.3 7.9 4.9 9.8 13.5 8.2 13.6 13.9 20.1 29.8 20.1 10.1 9.9 3.5 -3.7 + + + ± ± . + + ÷ ± + + ± ± 4.9 3.0 3.9 5.0 3.9 3.8 4.6 5.0 3.5 3.4 8.2 3.2 2.3 5.3 10.8 7.8 10.0 13.6 8.3 20.8 22.7 26.9 29.9 18.5 11.2 7.4 4.0 3.1 9.3 ± ± ± ± ÷ ± ± ± _ ± ± 9.0 5.3 8.1 18.8 13.6 14.6 26.0 33.7 26.2 17.7 T 8.5 7.8 4.1 -0.6 + + ± ± + ± ± + _ 4.3 4.8 3.0 6.2 3.3 2.4 5.9 4.8 2.8 2.9 3.0 3.4 2.0 1.1 + 6.4 3.3 3.7 3.7 2.4 3.5 3.2 3.3 3.1 2.8 2.6 2.9 1.8 1.6 5.5 14.5 ± 13.2 13.4 ± 5.0 12.2 ± 6.6 16.8 ± 7.0 12.9 t 3.4 13.6 ± 4.3 0.2 ± 4.0 18.8 + + + + _ + ± + + + ± + + + + + + ± + + _ 3.0 2.6 2.5 2.2 2.3 2.1 2.4 2.3 2.1 2.6 2.6 2.1 2.2 1.3 1.3 1.3 14.5 ± 9.7 ± 15.0 ± 16.2 ± 18.8 + 15.8 ± 21.7 28.5 ± 37.2 ± 41.1 " 21.5 + 9.2 ± 5.31 2.8 1.2 " 1.9 + 0.9 + 0.8 4 8.6 4.0 3.3 3.0 2.8 2.1 2.3 2.6 2.6 2.7 2.0 2.7 1.6 1.4 0.9 1.2 1.0 0.8 32.2 8.0 17.0 11.8 14.3 12.8 22.6 26.7 25.7 29.1 20.8 10.2 6.7 2.2 2.7 2.7 0.3 + 51.6 + 3.8 ÷ 4.3 ± 3.7 _ 2.9 ± 2.5 ÷ 2.5 + 3.6 + 2.9 + 3.0 + 2.4 ÷ 2.3 t 2.1 ± 1.4 ± 1.4 ÷ 2.1 " 2.4 .P = 66 GEYV/Ct 5.1 5.7 6.9 11.5 7.7 14.4 14.7 17.9 26.2 29.7 27.9 15.9 8.1 6.7 2.1 2.3 2.3 13.1 9.5 12.2 11.1 7.1 13.0 22.9 23.4 30.1 20.9 10.3 7.1 6.9 2.8 4.8 1.2 4.2 3.5 3.2 3.5 2.3 2.1 3.3+ 2.6 " 2.9 + 2.9 + 2.7 2.5 + 2.0 _ 2.0 ÷ 2.9 t 1.3 1.1 P = 6.2 GEV/C 1 -1 I 0.005 12.2 10.2 13.0 12.7 15.9 22.3 23.2 30.6 38.6 39.9 25.8 15.1 9.0 4.3 2.9 0.7 0.4 1.0 ± ± _ ± + + ± ± ± + + ± + + ± + ± ± 4.9 2.3 2.0 1.9 1.6 1.4 1.4 1.7 1.9 1.8 1.4 1.4 1.2 0.9 0.7 0.9 1.0 0.7 SI 495 1 525 I 32.5 ± 15.6 555 1 12.5 + 3.3 9.1 ± 4 ± ± ± _ 585 I 14.5 ± 2.5 15.2 ± 4.0 615 ÷ 2.6 14.9 ± 3.8 9.0 + 3.3 13.0 ± 5.2 645 I 24.5 675 I '24.8 705 I 32.4 735 1 40.3 765 1 43.9 + 2.1 22.2 - 3.1 15.4 ± 3.4 18.1 + 3.4 15.8 + 5.8 + 1.7 21.7 ± 23.6 ± ± ± 1.9 2.2 2.4 37.8 _ 3.2 39.0 ± 3.3 39.9 ± 3.0 I 28.8 1 14.8 1 7.3 I 4.7 | 2.0 I 2.2 1 1.3 I 3.1 ± ± ± 1.7 1.1 1.1 1.0 0.8 0.6 0.6 2.2 24.3 14.4 7.9 2.7 1.0 1.5 795 825 855 885 915 945 975 1005 1 18.0 + + ± ± + ± ± 2.0 ± 5.3 - 3.2 14.5 + 3.0 12.0 ± 2.7 30.0 + 43.2 + 35.9 ± 2.8 4.2 4.2 29.6 + 26.2 ± 26.5 + 4.1 3.2 3.5 22.4 ± 26.0 ± 29.1 ± 3.5 5.2 4.2 2.4 22.2 _ 1.9 11.3 1.4 7.5 ± 1.1t 1.6 + 0.6 0.6 0.8 -0.1 + 4.1 + 2.0 2.5 1.8 2.2 1.3 .7 0.9 3.4 20.5 11.5 2.7 3.6 3.3 1.3 3.5 2.1 1.9 2.0 1.5 1.2 14.5 9.7 3.1 0.6 0.4 5.5 2.5 Fig.17a _ + + + ± " 2.5 ± 2.9 " 1.6 . 1.6 ± 1.4 ± 4.1 1.7 ± 1.8 -90- CARBON -1 -T = I 0.001 in pb/sr.MeV/c d 1 ___- __A, 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 I 10.9 + 1 14.9 ± I 13.1 + 1 17.1 ± I 16.8 + I 22.2 + ] 26.6 + 1 31.1 ± 1 40.8 + I 39.8 ± I 26.8 + I 16.2 + I 10.6 + 1 6.6 + 1 3.3 + i 1.4 + I 0.3 + I 1.4 + 1.8 1.9 2.1 2.0 1.5 1.8 1.7 1.5 1.6 2.0 2.0 1.8 1.6 1.3 0.8 0.6 0.3 0.8 0.003 _1 : 5.2 13.7 10.8 11.1 13.1 20.2 25.3 26.8 31.3 35.4 23.8 17.7 4.0 2.1 4.0 1.2 0.0 + + + + + + + ± + 4 ± + + t + + ± .I. ml Z vs. m(MeV/c2 ),p(GeV/c) and t. (GeV/c) 2 0.005 ] _-. I 0.009 8 GEYLf..- _ 5.0 11.4 7.4 13.4 18.8 14.2 20.2 27.0 34.9 34.7 13.8 18.9 7.1 0.3 1.9 2.0 2.2 1.0 3.4 3.2 2.5 2.6 2.3 2.5 2.7 2.4 2.2 2.9 3.8 3.0 2.1 1.3 1.2 0.6 0.8 0.007 1 + + + + + + + + + + + + ± + + + + 2.6 3.2 2.9 4.0 3.8 2.3 3.2 2.7 3.1 3.6 3.8 4.5 2.3 1.4 1.2 1.1 1.3 1.3 6.2 10.2 11.1 10.6 11.3 8.4 12.0 24.2 31.5 23.0 17.9 10.9 10.5 1.9 3.2 2.9 -0.4 + + + ± ± + + + ± + 4 + + ± + ± . 3.6 3.5 3.8 5.1 4.9 5.2 2.9 3.3 3.0 3.5 8.2 4.1 4.2 1.9 1.9 1.3 2.2 6.0 4.9 9.4 12.0 13.5 12.5 16.3 16.4 29.8 20.9 8.6 10.7 0.2 -4.2 3.1 0.8 2.0 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 I 15.1 ± I 22.5 + I 27.2 + 1'25.3 + I 32.5 + 1 47.5 + I 54.1 ± ) 46.1 . I 34.0 ± I 17.6 + I 8.6 + I 6.0+ 1 3.2 + I 4.2 + 1 2.5 + I 1.3 + ,6.= 9.7 3.2 2.8 3.0 2.3 2.0 2.3 2.5 2.4 1.8 1.2 1.2 1.1 0.9 1.0 0.8 0.6 24.3 23.0 25.2 13.7 24.3 32.7 40.9 44.4 48.0 31.1 18.4 11.8 7.5 5.9 2.6 2.3 1.2 3.8 2.6 4.5 5.5 5.0 3.8 5.0 4..6 3.4 3.4 9.1 4.0 1.8 5.9 2.8 0.9 1.6 ± + + + + + ± + + + + + ± +± ± - 3.8 4.8 3.0 4.5 4.1 2.6 6.8 4.9 2.9 2.9 4.3 2.5 3.4 2.1 3.7 1.0 + + + + ± + + + ± + ± + ± + + ± 6.7 6.2 5.3 5.3 4.2 3.6 5.4 4.3 2.8 2.8 1.7 3.3 2.2 4.6 3.1 1.1 P__•= 6.2 GEYtC 5.4 + 52.7 495 I 14.4 + 4.2 -3.8 + 8.7 98.9 , 79.6 9.5 525 I 12.2 + 2.5 13.5 - 3.9 11.5 + 3.8 19.1 ± 7.4 2.6 8.6 + 3.2 13.4 + 3.6 555 1 14.4 + 2.0 14.2 + 3.1 7.2 16.2 + 3.6 17.3 ± 4.5 18.0 + 5.2 585 I 18.4 + 2.1 9.3 615 ) 16.6 + 1.9 18.8 ± 3.5 19.9 " 3.6 19.2 + 4.9 3.2 15.8 645 I 22.9 ± 1.6 22.1 + 2.7 14.2 + 2.8 11. 675 I 31.4 " 1.7 25.8 + 2.6 23.5 + 2.7 18.1 + 3.3 15.6 705 1 37.5 + 1.9 35.3 ± 2.9 33.5 - 3.8 27.6 + 3.5 34.5 3.1 34.3 - 3.6 37.4 2.9 33.6 . 735 I 46.4 + 2.1 46.6. 765 I 46.6 + 1.9 47.3 + 2.9 37.8 ± 3.4 36.6 + 3.3 29.5 795 I 32.4 + 1.6 21.5 + 2.0 25.9 + 2.7 15.3 + 2.7 18.2 1.7 16.6 ± 3.5 15.4 4.5 . 17.6 ± 1.5 19.2 ± 3.7 825 5.2 9.0 ± 1.9 12.4 ± 3.2 13.5 ± 4.3 8.8 + 1.4 855.1 4.2 6.9 + 3.0 1.3 ± 1.1 6.1 + 2.0 885 ) 5.6 + 1.2 1.7 5.1 ± 2.8 6.3 + 3.9 3.9 ± 1.4 915 I 2.7 ± 0.7 5.5 4.8 ± 2.4 1.5 t 1.1 0.5 + 0.8 945 I 2.9 + 0.8 1.7 1.5 + 0.9 0.0 + 1.1 1.9 + 1.0 975 1 2.0 + 0.8 1.0 + 0.8 0.0 ± 0.8 1005 1 0.9 + 0.4 --------------------------------------------------- _. 495 l 525 1 16.5 + + + + + + ± ± + . + + ± ± + + + + g_, 6-6 GFV/C -- + 16.1 - 6.5 ± 5.0 + 4.1 + 3.5 ± 3.2 + 3.4 ± 3.6 + 3.2 ± 2.7 + 2.1 + 1.8 + 1.9 + 1.9 + 1.2 + 1.1 ± 0.9 32.9 16.5 6.1 20.1 18.6 25.1 33.9 42.0 40.4 24.5 17.8 6.6 1.2 5.2 3.2 0.71 ± 17.2 + 5.1 + 2.7 ± 5.1 + 3.7 ± 3.5 - 3.0 + 4.1 4.4 ± 2.7 - 2.1 + 2.5 + 2.1 . 2.0 + 2.3 1.4 Fig.17b 13.0 ± 17.9 23.8 ± 7.1 7.6 - 3.3 4.6 + 5.8 18.1 + 3.8 24.8 + 4.2 3.7 24.4 4 39.3 + 3.9 3.8 32.3 25.5 ± 3.8 8.7 ± 1.8 7.2 ± 2.9 4.0 + 3.6 4.5 + 2.0 1.6 ± 1.6 2.7 ± 2.8 20.9 17.8 8.8 11.5 19.3 22.8 31.4 32.9 19.7 8.8 4.0 4.9 3.6 6.0 -1.5 1.3 -91- ALUMINIU4 -r = 1 _ L d24-0 A MR~ii 0.001. pb/sr.MeV/c 2 0.003 1 i. 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 1 17.6 ± I 15.6 ± 1 23.4 ± 1 23.8 + I 26.3 + I 30.8 + 1 32.5 ± I 51.4 _ 1 68.1 ± I 61.7 + I 40.7 I 24.3 ± 1 17.6 ± I 7.3 4 I 4.0 4 I 1.6 _ I 1.6 ± I 3.4 + -- If I 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 in _.ep =-S& 3.8 2.9 3.2 2.8 2.3 2.5 2.5 2.5 2.6 3.1 3.2 2.7 2.5 2.0 1.6 0.9 1.3 2.5 12.8 17.3 20.8 16.6 12.9 27.0 34.8 39.8 49.4 53.2 27.3 26.3 18.6 6.3 3.7 .2.4 5.7 11.5 + 5.6 ± 5.0 4 4.1 + 4.2 + 2.9 ± 3.8 + 4.5 ± 3.7 ± 3.4 ± 4.5 ± 4.9 + 5.1 ± 5.1 ± 2.9 ± 2.1 ± 1.7 ± 4.1 _ 12.2 7.6 3.8 3.5 3.5 2.8 2.5 2.7 3.3 3.6 3.1 2.4 2.4 2.4 1.9 1.3 1.9 2.4 15.9 11.2 21.5 20.3 27.4 23.6 41.1 45.2 61.5 67.4 31.7 25.9 8.9 8.7 1.4 2.8 3.5 ± 11.4 4 6.5 - 5.4 ± 4.4 ± 4.3 ± 3.6 ± 4.2 ± 4.3 + 4.3 + 4.3 ± 3.1 + 6.0 + 2.9 ± 3.5 1.5 ± 2.2 + 2.3 1 0.005 10.0 11.2 14.5 18.3 11.0 16.7 19.6 28.2 45.0 45.7 46.9 15.8 8.0 1.6 2.4 3.7 2.6 1.6 EYLC + + + +4 ± + + ± ± . ± ± 4 ± 4 5.4 5.0 4.5 5.9 3.7 3.3 4.1 3.7 4.5 5.3 6.8 4.8 3.0 3.0 2.7 2.8 2.8 3.1 1005 1 3.6 _ 1.5 -: 10.6 14.3 6.9 6.5 7.8 6.6 27.1 30.9 41.5 35.8 32.0 6.8 16.4 5.3 4.6 ± 9.7 5.3 4.4 4.9 5.2 5.3 5.4 4.9 4.3 5.4 .10.4 4 3.8 ± 6.4 ± 5.1 2.7 4.2 0.009 4.3 14.4 11.4 2.0 9.3 20.6 15.8 23.5 36.5 31.4 50.1 20.4 4.4 0.5 ± 4.8 + 6.0 ± 5.9 + 2.9 ± 5.3 + 6.0 + 6.9 + 7.0 . 4.7 + 5.2 + 26.0 ± 6.2 ± 3.3 .15.2 2.8 ± 3.6 ± 3.2 4.1 . ± ± ± ± ± ± + ± ± + + ± 5.8 6,9 3.8 2.9 4.1 3.9 7.9 6.0 4.3 4.1 6.4 5.1 2.6 2.1 7.5 2.6 tF,6 G=Y.--_6eC- 37.4 ± 12.4 9.7 ± 6.3 11.2 + 5.5 -0.7 ± 7.0 ± + ± + 7.6 3.9 4.6 5.7 5.1 14.3 18.1 35.3 ± ± ± 4.8 7.0 4.7 5.9 6.2 47.4 ± 5.8 46.6 ± 9.1 7.2 3.9 2.8 50.0 ± 27.1 18.6 ± 6.2 5.2 3.3 36.5 + 25.2 ± 14.5 ± 5.8 4.3 4.7 14.6 + 3.9 8.1 - 4.1 6.9 + 3.5 2.9 + 1.9 4.4 ± 3,1 1.9 - 3.7 8.1 +÷ 2.9 6.0 4 2.9 5.2 + 3.5 2.1 4.9 ± 3.1 4.5 + 3.7 + 2.8 2.8 6.4 + 5.4 + 4.8 27.0 ± 11.2 17.3 + 5.9 14.0 23.0 ± 645 I 38.0 ± 675 I 47.6 ± 705 I 65.6 ± 4.3 3.4 3.1 3.6 24.1 25.2 39.3 52.1 ± ± ± ± 6.5 4.4 4.4 5.1 22.4 30.2 36.6 52.0 ± + ± ± 6.9 6.3 5.1 4.8 14.4 11.2 16.8 33.9 735 I 77.5 + 765 1 78.5 + 4.0 61.4 ± 5.6 53.4 + 795 I 55.7 + 825 I 33.2 + 4.1 3.0 2.0 65.0 40.8 + 22.9 ± 5.0 4.0 2.9 55.7 + 30.7 ; 17.4 + 16.9 + 2.0 17.5 ± 2.7 10.1 ± 1.8 5.2 ± 2.2 7.8 + 1.9 2.8 2.9 ± 0.6 + 1.1 0.7 7.4 ± ÷ 1005 I 1.1 + 11.3 0.8 7.2 0.0 9.2 19.5 25.2 27.6 37.6 24.5 20.7 5.0 3.7 -0.2 6.5 2.2 11.8 : 15.1 9.0 ± 10.6 _ 7.3 . 91.0 198.5 ±203.3 - 6.5 23.4 ± 11.7 5.1 ± 3.9 ± 5.6 14.0 ± 6.1 ± 5.9 4 4.3 14.7 . 5.1 8.2 + 3.9 ± 4.5 ± 3.6 30.4 ± 5.6 . 6.3 31.1 4 5.0 + 4.9 46.8 ± 5.8 ± 5.0 52.2 4 4.8 4 3.7 19.8 ± 4.0 + 3.3 10.8 + 3.4 6.8 - 3.8 ± 2.6 6.7 ± 3.2 . 2.6 3.6 ÷ 3.9 2.5 - 2.5 11.7 ± 8.4 1.8 + 1.9 t 2.8 2.6 .. P -.. 40.6 56.3 12.3 16.9 15.3 16.3 24.7 27.3 50.5 46.5 51.8 32.2 12.5 5.3 3.7 5 .5 2.• -1.4 4.7 975 I ± ± ± + + + ± ± ± - 3.5 3.8 ± 28.6 + 855 I 885 1 915 1 945 I 1 0.007 P =P 62 GEFYV/C I 14.3 ± I 14.5 + I 22.7 + I 23.7 + I 26.4 + I 37.3 + I 47.5 + I 65.4 + 1 83.8 ± I 73.0 ± I 47.7 + I 30.0 + 1 18.5 + I 9.7 ± 1 4.3 + I 2.3 I 4.4 ± M__I 495 I 525 1 555 I 585 I 615 I m(MeV/c2 ),p(GeV/c) and tl (GeV/c)2 vs. S 3.1 1.6 0.5 1.2 Fig.17c -92- TITANIUM -T = -,~ M 1 in pb/sr.MeV/c2 vs. m(MeV/c2),p(GeV/c) and t1 (GeV/c) AA 1 0.001 I 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 I 0.003 P = ----5.8 GFV/C -,, 5.4 + 5.9 --~-- 23.5 23.4 32.9 30.1 32.2 43.7 52.6 55.6 81.0 86.2 55.4 35.2 22.8 8.8 4.4 3.9 0.0 1.3 + + + i ± + + + ± + + + + ± ± ± ± + 5.1 4.0 4,3 3.8 2.8 3.3 3.6 3.4 3,8 4.9 4.7 3.9 3.4 2.7 2.0 1,8 1.2 2.6 12.1 17.4 18.4 20.4 14.9 30.9 32.2 58.4 62.4 61.0 36.0 23.4 13.0 3.9 5.5 1.8 + ± + + + + + ± +± ± + ± + + ± ± 4.2 + i 0.005 7.3 6.3 4.4 5.4 5.4 4.7 5.1 5.6 5.0 6.4 6.8 6.1 5.2 3.0 3.3 1.8 11.3 6.1 8.6 20.2 26.2 31.2 39.9 53.1 59.5 27.4 25.6 16.6 0.0 5.2 + _ + ± ± + + + + i ± + ± 1.7 + 5.8 3.5 5.4 5.4 4.4 5.8 5.6 6.6 7.7 6.9 7.4 4.8 2.6 4.2 3.5 0.007 I ,, 0.009 ,-,, 0.5 ± 10.4 0.1 + 2.8 16.6 ± 6.9 9.4 + 6.8 21.7 " 7.5 4.5 4- 6.5 11.3 ± 4.8 28.6 i 6.2 47.4 +4 6.2 23.1 + 6.4 56.8 ± 16*2 14.1 ± 6.5 13.9 + 6.9 10.0 + 11.1 9.28 8.2 3.9 4 3.9 7.8 + 6.8 11.4 3.0 8.0 12.2 -0.8 15.7 24.1 18.0 29.8 14.8 9.0 11.4 1.1 -8.3 P. = 6..-.24EY/C 525 5.5 19.0 + 555 I 23.8 ± 4.2 21.9 ± 6.8 585 | 39.0 + 615 1 33.0 ± 5.1 3.6 37.0 ± 34.2 ± 645 I 46.2 ± 3.1 38.9 ± 5.2 26.4 " 5.3 11.4 + 4.8 675 3.3 37.5 + 4.6 4.2 22.8 + 5.3 53.5 + 30.1 + 20.5 5.4 46.7 6.7 37.7 + 6.3 21.2 4.9 4.6 3.7 3.5 3.2 2.5 2.0 75.6 ± 75.4'± 45.1 ± 17.9 ± 24.0 ± 3.9 ± 5.3 + 6.0 6.1 4.8 6.5 5.1 3.6 2.7 58.0 48.9 36.2 16.3 9.9 12.8 4.5 7.0 6.4 5.4 4.6 4.1 4.9 2.8 46.1 55.2 34.6 17.2 18.8 8.3 4.4 7.1 6.6 6.5 5.3 7.2 4.2 3.0 43.2 44.3 21.5 13.1 12.2 2.2 1.2 1.9 2.4 + 3.8 1.4 + 2.0 0.1 - 5.9 2.9 + 3.0 705 735 765 795 825 855 885 915 I 70.1 + 4.0 1 1 1 I I I 97.3 99.5 63.7 37.5 23.1 11.2 I 8.4 + + + + + + + 945 1 0.9 ± 975 I 3.0 + 1005 I 2.7 ± 2.9 1.6 2.0 ± I 48.8 + 28.9 I 31.9 + 8.1 1 32.5 + 6.0 1 38.1 + r%47.4 + 1 63.9 + 1 94.2 ± 1118.3 1112.7 I 77.5 I 45.3 I 28.3 I 14.8 I I I I 9.4 6.6 5.4 _ .. 1M 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 ± + + + + + 8.7 5.8 + 3.4 + 4.7 6.0 4.5 4.0 4.8 5.5 5.8 4.5 3.0 3.3 2.8 2.5 1.7 1.6 2.6 27.3 33.6 30.8 40.5 46.0 72.5 79.0 95.9 58.0 31.5 24.7 11.9 7.3 3.6 6.5 2.5 3.4 8.3 21.4 ± 15.3 I 58.1. 9.2 3.0 5.2 6.5 2.0 5.8 9.4 8.9 6.0 5.5 13.6 5.6 3.2 11.8 1.7 ± , I 495 I 18.9 + 10.5 I 22.1 + 2 133.1 ±139.3 14.6 + 8.9 3.9 ± 7.8 20.7T 7.5 4.2 t 4.4 3.9 + 10,2 13.4 + 27.4 ± 6.7 6.0 2.4 + 9.4 + 4.1 4.1 4.5 ± 9.8 + 3.9 7.0 7.5 4 6.0 + + + + + + ± . ± ± + + 14.3 ± " + + + ± + + ± + 7.2 4.3 8.1 8.8 6.0 5.2 6.0 8.0 3.1 2.3 20.5 ± 26.0 2.8 2.7 + 2.7 18.6 ± 17.5 2.3 + 4.7 P = 6.6 GFV/C ± 14. 1 ± 9.0 ± 8.6 + 6.3 + 5.5 ± 6.7 ± 7.3 ± 7.1 + 6.0 + 4.4 + 4.1 + 3.6 + 3.2 ± 2.1 + 5.1 ± 2.8 23.9 11.9 22.4 16.1 39.7 51.1 52.8 61.4 38.0 19.8 8.2 11.5 4.1 4.2 3.3 13.1 11.4 5.6 7.8 6.3 5.9 5.5 7.0 9.1 5.3 4.1 4.4 4.6 2.7 3.7 4.6 8.1 Fig.17d 24.2 24.5 12.0 21.4 19.9 44.6 46.3 48.2 27.8 24.0 13.8 17.8 4.9 4.4 5.2 + 12.5 ± 8.5 ± 8.6 + 5.6 ± 5.9 + 7.2 + 6.3 + 7.9 ± 7.1 + 4.7 ± 6.4 + 7.4 ± 3.0 ± 6.2 + 5.9 5.3 -3.6 13.3 28.0 22.3 36.7 40.4 35.4 18.4 11.8 6.8 1.9 0.7 7.5 6.4 ± + + + + ± ± + + + ± ± + + 6.0 7.8 7.5 11.1 5.5 6.7 9.2 6.6 5.3 5.6 4.0 4.1 3.3 6.5 7.0 -93- COPPER ?-d pb/sr.heV/c 1 0.003 in m -T = i 0.001 S_ 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 20.4 19.3 23.0 27.1 34.8 42.4 57.2 72.0 95.4 95.7 68.7 36.2 29,6 5.7 4.6 5.6 2.8 7.3 4.2 3.7 4.9 5.6 3.9 4.0 3.6 3.5 3.9 4.7 5.0 4.1 4.1 2.5 2.4 3.2 1.7 4.3 14.8 11.4 17.0 29.8 22.3 34.4 43.0 54.6 69.0 54.7 38.7 32.4 18.3 16.9 5.8 6.8 0.3 .MI 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 1 25.4 1 31.5 1 28.4 i 43.7 I 28.3 I 52.8 1 66.0 1 90.1 1110.5 1110.5 1 I 1 I I I 74.9 45.2 25.9 13.9 8.7 8.4 1 2.8 I 3.4 I 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 1117.0 ± 1116.7 + I 87.7 ± 1 43.4 ± 1 25.3 + I 17.7 . 1 7.4 + I 6.8 ± I 4.5 + I 4.4 vs. m(MleV/cZ),p(GeV/c) and tz (GeV/c) 1 8,9 6.1 7.3 6.4 4.4 4.8 5.4 5.2 4.9 5.8 7.7 6.8 6.2 5.2 3.2 3.4 4.7 2 0.005 I 0.007 I 0.009 GE-------------------------------------------------- 20.7 13.0 19.9 16.7 8.0 5.7 7.6 7.1 5.7 4.5 6.2 5.2 6.5 6.8 8.7 7.5 4.5 3.8 2.9 3.9 22.3 28,0 34.8 38.5 59,5 48.7 39.6 23.2 11.9 3.2 1,4 5.2 -- 5.2 6.6 7.4 5.3 6.3 9.5 5.3 5.1 5,6 5.8 14.9 4.9 9.3 17.1 -1.0 2.0 14,0 20.6 20.7 45.3 22.1 20.8 30.0 2.2 7.7 3.2 2.4 -2.1 ---- - 13.5 2.4 12.4 7.5 12.4 13.6 33.8 33.9 20.0 15.8 22.8 11.1 17.3 5.1 6.2 7.7 -7.7 5.1 2.6 11.4 2.5 ± 9.8 2.4 8.1 5.9 6.5 5.1 10.1 9.9 4.6 5.0 21.6 8.5 5.3 10.9 5.0 P_= 6.2 GEVlYr 9.1 6.7 5.0 5.2 3.9 3.4 3.4 4.3 4.9 4.5 3.9 3.7 3.6 2.8 2.2 2.7 2.0 1.8 -11.2 36.4 19,2 34.6 24.2 34.4 41.9 61.2 84.7 80.0 47.7 11.4 16.5 16,7 2.4 7,3 2.1 -0.7 24.2 10.1 6.5 7.7 6.1 4.8 4.6 5.6 5.8 5.8 4.7 5.0 4.0 4.8 2.3 4.4 2.3 3.8 15.7T 17.6 + 20.2 ± 7.8 7.9 8.5 37.2 + 7.2 18.4 + 4.6 31.7 + 4.4 45.9 + 6.2 53.5 ± 6.1 55.8 + 6.3 36.6 + 5.1 6.6 +4 3.7 20.9 + 6.7 4.5 + 4.7 2.8 + 2.9 6.1 + 4.9 2.7 ± -6 1 21.3 ± 17.8 I 15.2 + I 46.9 ± I 42.4 1,57.3 + I 68.1 + I 96.4 +± 2 6.2 6.6 6.2 5.1 4.1 4.6 5.1 5.6 4.4 2.8 3.1 2.8 2.1 2.1 1.9 4.5 -55.7 16.5 21.9 111.3 11.6 7.2 6.8 6.1 5.3 5.3 5.4 6.2 7,4 12.5 14.8 24.7 33.9 38.9 41.5 31.8 9.9 0.0 6,0 11.0 5.5 5.8 3.6 5,3 4,2 7.2 2.8 8.8 ± 5.3 1.0 + 10.9 10.6 ± 6.0 -006 + 3.7 17.8 + 8.3 10o3 S3.1 7,7 . 20.6 10.2 + 5.1 26.4 + 4.6 19.7 + 4.6 11.0 + 5.4 12.7 + 6.1 -0.5 + 1.5 1.4 + 6.2 8.4 + 10.6 2.9 + 3.5 4.4 + 4.5 GC----------------------- 41.7 38.6 31.1 22.5 30.7 46.0 78.1 83.9 86.2 62.6 34.1 21.8 9.2 6.1 6.8 4.4 3.9 ± 33.1 + 14.1 + 9.6 - 9,.8 + 6.1 ± 5.5 ± 6.5 ± 7.0 ± 6.4 + 5.7 ± 4.3 + 3.6 4 3.4 ± 3.2 + 3.0 ± 2.7 " 3.0 13.5 10.2 28.7 17.7 21.2 43.1 47.5 61.1 50.1 46.7 30.3 5.8 6.0 3.7 -0.7 11.2 17.3 6.5 8.3 8.9 6.1 6.3 5.0 6.9 7.5 5.5 4.4 4.6 5.6 2.9 1.4 6.7 Fig.17e 55.5 3L.4 17.2 16.6 22.2 29.9 43.0 42.2 44.7 27.5 16.3 2.8 9.6 1.2 6.1 7.4 10.2 + 60.3 4 13.3 13.7T + 17.1 4. 7.9 4. 15.3 + 6.4 + 7,0 ± 6.6 ± 5.8 + 6.9 ± 6.2 ± 3.8 ± 3.9 + 7.0 ± 2.2 ± 4.8 ± 6.0 + 12.0 -1.2 16.4 21.7 30.6 32.6 46.5 24.9 4.4 8.8 2.6 7.5 5.6 -8.7T 9.0 8.8 9.7 ± ± 10,7 + 8.4 ± 6.1 ± 7.6 ± 6.9 + 5.3 + 4.0 ± 3.9 + 6.0 + 4.9 + 4.1 17.3 -94- SILVER 1A -T = I 0.001 -M-I in pb/sr.MeV/c2 vs. m(MeV/c ),p(GeV/c) and t. 1 0.003 - I i 0.005 5.1 4,4 4.2 4.3 3.1 3.3 20.0 11.2 22.2 25.4 28.6 33.8 ± ± ± ± + ± 675 I 61.7 + 7.8 5.2 5.0 5.7 4.4 4.1 3.3 43.4 + 4.8 23.8 + 4.0 3.5 3.9 4.8 4.6 48.5 65.9 52.4 42.3 + ± ± ± 4.6 4.6 5.5 6.4 33.3 39.7 34.4 23.6 ± ± + _ + ± 3.1 3.0 2.4 2.8 1.9 2,3 14.0 ± 4.1 ± 0.8 4 1.5 ± 2.5 ± 4.5 2.6 1.5 1.6 3.2 + ± ± + + ± 4 + ± ± ± + ± ± ± ± ± 11.1 7.5 4.7 4.7 4.3 3.3 3.4 4.0 5.2 4.5 4.5 3.9 3.4 2.7 2.0 2.8 3.5 2.2 I 24.2 I 30.7 I 30.8 1 43.3 I 43.6 1 48.8 705 I 82.5 735 1102.8 ± 765 1100.1 ± 795 I 65.3 ± 825 855 885 915 945 975 1005 M 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 M 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 I 41.4 4 3.8 24.9 + 5.5 j 23.2 I 13.7 I 7.5 ) 10.6 I 2.7 1 2.3 I 25.7 19.5 27.2 33.7 33.2 43.0 58.8 84.4 81.5 44.7 33.1 20.2 7.2 3.6 4.0 ± 10.4 ± 6.1 ± 5.6 + 5.5 ± 4.4 4.2 + 4.8 + 5.5 ± 5.7 + 4.3 ± 7.6 + 4.4 ± 3.7 ± 2.3 ± 2.7 6.6 -0.7 5.9 2.3 3.0 20.2 10.5 13.0 23.7 22.0 28.0 40.2 54.6 50.5 32.3 10.6 8.9 7.9 6.9 3.9 -1.5 1110.0 1140.5 1135.3 1 95.5 1 58.1 30.2 1 16.2 10.0 I 6.6 6.1 7.5 - 38.4 4 8.9 +. 6.2 ± 6.6 + 5.1 + 4.3 + 4.5 + 5.2 + 5.5 + 4.4 + 3.2 ± 3.2 + 2.7 +± 2.4 1.7 ± 2.1 + 3.8 5.9 3.9 5.8 5.6 5.5 3.0 -1.2 7.5 4.2 6.1 5.4 1.8 4 + + 4 0.009 4 ± + + ± 6.9 4.1 3.9 5.2 4.3 4+ .2 16.4 ± 4.0 13.5 ± 5.2 4.1 4.4 4.6 9.7 17.1 17.2 10.6 -3.3 7.1 4.0 3.8 6.6 ± .4.5 17.4. + 5.3 30.0 ± + 5.5 12.2 + + 5.8 26.1 4 13.0 P = A.A I 86.3 1 43.9 1 37.6 I 53.2 1 '64.3 I 83.7 ± + 4 + 4 + I 2 5.0 2.2 3.7 4.6 1.3 10.6 ± 4 4 ± ± + + + + ± 71.9 28.6 37.6 19.9 49.7 57.4 73.8 84.3 88.0 69.8 35.1 20.0 13.5 8.0 3.3 3.1 5.8 45.7 13.3 6.4 9.5 18.7 7.2 25.3 7.0 26.5 5.6 29.6 45.4 5.9 6.3 51.4 5.9 51.3 5.8- 28.1 4.5 16.2 3.4 12.4 3.5 8.1 3.1 3.6 0.7 1.6 3.5 2.1 8.9 5.0 6.2 2.2 3.6 3.8 3.4 3.7 4+ .4 16.5 + 6.1 8.8 ± 3.7 2.9 1.9 4.7 2.4 3.2 4.4 + 3.8 3.9 + 5.5 6.8 13.6 1.2 + -5.4 + 3.0 7.6 3.2 ± 3.5 GEV/C + + + + 9.2 5.0 6.2 5.4 4.7 k ± 3.7 + 5.2 - 5.8 + 6.0 ± 4.5 ± 3.5 t 3.4 + 3.4 + 3.2 4 3.3 3.0 10.6 4.6 9.8 13.1 5.7 20.4 21.5 29.4 24.6 13.8 13.9 4.4 4.8 3.5 5.9 2.0 ± 10.3 + 3.7 ± 5.6 ± 4.9 + 3.3 + 4.3 ± 4.0 + 4.7 + 4.0 4 4.1 + 4.1 + 3.2 ± 2.7 ± 2.7 + 6.1 4 2.1 5.4 0.9 9.4 11.5 9.7 8.1 13.9 15.4 17.8 14.1 2.5 1.3 -0.5 -0.1 _ ± ± + ± ± ± + ± ± ± + 3.3 + I 1 9.3 3.9 21.1 8.5 22.6 18.0 P = 6.2 I 24.2 1 46.9 I 31.6 I 31.9 I 50.9 I 56.1 1 77.0 1101.3 1128.4 1113.3 I 88.9 I 56.4 I 31.6 I 16.1 I 9.8 I 4.3 I 6.7 I 5.6 0.007 P =-5.8 GEYLC / + 4 ± ± + 495 525 555 585 615 645 (GeV/c) C•vIr 6.5 6.3 8.3 7.0 5.0 4.5 5.6 7.1 4.2 3.3 4.4 3.4 2.1 2.5 4.7 7.2 Fig.17f 4.4 7.2 4.0 7.6 3.8 2.2 5.6 4.6 3.5 3.6 2.8 4.2 1.1 1.7 3.5 __,,, 54.8 3.1 11.2 15.1 25.5 19.8 26.5 35.8 30.8 16.1 14.7 3.9 4.6 2;0 3.0 5.0 + 65.6 +± 6.1 + 5.7 + 8.3 4. 6.1 + 5.3 + 4.9 ± 4.4 ± 5.3 ± 4.8 + 3.2 + 3.4 + 3.7 + 1.6 ± 2.8 + 6.3 -0.4 3.8 6.4 11.1 15.0 11.3 15.0 14.2 6.8 3.0 1.2 4.3 1.7 ± ± 4 + ± ± ± ± ± ± ± ± + 6.1 4.3 5.4 3.8 3.9 4.1 3.6 3.9 3.6 2.9 2.6 3.1 1.9 -95- in pb/sr.MeV/c CADMIUM -A -T = 1 0.001 M I 495 24.7 ± 525 32.2 4 555 34.0 ± 585 37.5 ± 615 45.9 ± 645 49.2 + 675 65.9 ± 705 81.7 ± 735 106.8 ± 98.9 + 765 795 71.9 + 825 40.6 ± 855 24.8 ± 885 14.8 ± 915 10.3 + 3.3. 945 975 -0.6 ± 3.6 " 1005 1 ) 1 I I 22.4 33.7 35.5 44.5 1 63.5 I 67.9 1104.1 1131.3 1125.4 I 86.6 1 49.3 I 24.0 1 14.1 I 10.4 I 4.1 I 2.0 + + ± ± + + + ± ± + + ± ± ± ± 1005 I 2.5 ± _ --.I 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 6.9 5.9 6.2 4.9 3.8 3.5 4.6 6.3 5.6 4.9 4.2 3.8 3,1 2.3 4.4 3.7 1.9 + ± ± ± + + + ± + ± ± ± ± ± ± + + + + + ± ± + 4 ± + + 8.6 7.9 6.4 6.3 4.5 4.7 5.0 5.7 5.7 7.0 7.0 7.0 5.0 4.0 5.6 4. 3.7 2.4 ± 2.5 4.0 . 5.1 17.1 20.2 25.8 32.6 28.9 40.8 66.3 79.3 82.8 46.7 22.8 13.3 0.4 3.3 2.2 3.0 + 11.7 + 8.0 + 6.5 + 6.1 - 5.1 + 4.7 + 5.9 + 6.3 ± 7.1 + 5.5 + 9.3 ± 5.3 ± 3.1 ± 2.6 ± 3.3 ± 3.3 5.5 ± 8.7 6.0 4.9 5.3 5.9 6.6 5.4 3.7 3.9 3.7 3.3 1.9 2.2 2.0 45.2 18.2 38.8 48.4 74.1 99.4 79.9 59.2 31.5 24.2 19.0 16.4 5.0 8.3 4.5 4.0 ± 14.4 ± 11.7 ± 9.4 ± 7.1 + 6.1 ± 6.5 ± 7.7 - 6.9 ± 6.3 ± 4.9 + 4.3 + 4.6 ± 4.5 ± 2.4 + 5.0 ± 4.7 0.005 I 0.007 I 0.009 - Soo GFV/C 9.9 8.6 7.3 12.2 13.7 5.5 6.7 6.1 5.0 12.5 3.6 19.4 4.8 26.4 5.4 24.3 6.6 42.2 35.1 7.2 28.2 7.2 4.4 11.8 14.6 4.3 4.9 6.7 5.3 4.7 7.5 14.8 4.7 5.0 ± 12.2 + 4.9 + 7.0 + 7.6 4* 7.7 3.4 4" 6.2 13.7T 4.6 17.3 4. 6.1 4.9 22.7T4 12.3 ± 6.1 16.1 _+ 8.5 18.8 4+ 6.9 3.5 +4 3.9 4.4 4. 6.2 -0.5 6.4 11.9 10.0 21.5 6.3 5.3 4.2 7.4 2.7 9.1 7.7 7.8 3.9 4.1 4.5 4.2 3.8 5.2 8.1 5.1 4.3 16.0 4.7 4.2 24.0 6.9 12.6 17.0 5.9 16.8 11.2 5.5 10.8 6.4 3.4 3.00 - 6.2 GevY/C 26.6 ± 19.2 -- 1 47.0 + 32.1 .10,4 I 34.8 1 46.2 ± 8.3 I 9.0 14.0 32.7 21.7 21.4 32.6 31.4 42.5 61.5 56.7 37.0 29.2 12.6 11.2 2 ---- 1 0.003 ---_ 67.3 .61.2 1 85.5 1117.0 1147.0 1153.6 1101.2 1 55.3 I 30.7 1 21.4 1 12.0 1 6.2 I 5.4 vs. m(MeV/c2),p(GeV/c) and tL (GeV/c) P 6.5 5.5 5.2 4.6 3.5 3.5 4.0 4.3 4.9 5.9 5.8 4,7 3.8 3.9 3.7 2.0 1.3 3.7 _•_I_P _ . 495 I 32.5 4 15.7 525 555 585 615 645 675 705 735. 765 795 825 855 885 915 945 975 2 P 19.5 12.0 12.4 23.5 21.7 35.2 41.6 46.9 47.9 32.6 20.0 13.4 5.2 4.6 _ 12.0 ± 7.1 7.9 ± 6.1 + 5.3 ± 4.5 + 6.1 + .6.9 + 7.2 ± 5.8 + 5.5 + 4.4 + 4.0 ± 2.9 -0.0 + = 7.6 30.9 15.6 15.4 14.3 6.8 19.1 14.6 27.6 29.4 12.8 16.3 6.9 4.2 7.1 + + ± ± ± ± + + ± ± + + + 3.2 + 18.5 7.2 7.9 5.7 4.7 4.9 4.5 5.9 5.6 5.4 4.5 4.5 2.6 4.6 24.4 10.8 7,5 8.0 8.0 6.0 5.3 6.6 8.2 5.7 4.7 5.7 3.8 3.0 3.2 8.7 9.2 5.2 9.8 3.0 3.1 6.5 6.5 4.3 3.9 4 6.1 + 7.2 + 2.8 ± 2.5 4 9.4 --- 18.4 14.4 2.5 6.5 18.7 27.8 43.8 27.2 5.1 7.9 8.3 5.1 1.4 11.4 ± 13.5 ± 7.9 + 9.1 ± 4.2 + 6.4 ± 5.9 ± 5.5 ± 6.6 ± 5.7 ± 3.7 + 5.6 ± 3.6 4 2.3 - 11.5 13.5 ± 16.0 Fig.17g + ± ± ± + ± ± ± f + 3.2 6-6 EY- 18.8 ± 16.2 _ 18.8 + 17.7-1 18,7 ± 34.4 t 46.3 ± 59.3 + 45.8 + 36.7 + 22.0 ± 14.6 6.6 ± 5.4 + 1.0 + 16.8 -5.2 12.0 17.7 3.6 13.5 15.2 22.4 15.0 8.7 7.0 2.5 4.5 0.4 7.8 12.3 3.2 8.3 4.4 5.9 15.7 16.6 23.9 11.7 9.1 4.9 4.3 1.7 + 10.2 ± 10.7 + 6.5 ± 6.0 ± 3.5 " 4.8 ± 5.4 + 5.1 ± 4.8 ± 4.9 ± 4.4 ± 4.2 ± 2.3 3.5 + 3.9 -96- INIUM - -T = 1 0.001 __r in pb/sr.MeV/c 2 vs. m(MeV/c 1 0.003 -1 495 525 555 585 615 645 675 705 735 765 795 825 855 885 I 31.7 - 6.2 I 28.0 I 34.2 I 40.7 ! 43.6 I 51.7 J 57.7 I 81.4 1103.3 1104.2 1 71.4 I 37.6 I 19.2 I 11.0 3.9 11.5 26.8 16.5 26.6 27.9 42.7 48.9 59.5 61.3 36.2 33.1 12.3 11.5 1 1 0.005 .___,=-5.8 GE-ILr 6.0 6.2 5.7 5.3 4.6 4.5 5.7 5.4 5.1 6.7 6.4 6.3 4.6 4.1 0.3 7.6 9.5 8.4 5.4 11.9 23.1 23.2 43.2 46.7 28.7 12.6 10.7 2.3 t + + + + + + + + + + + t 5.0 5.2 4.3 5.4 3.4 3.1 4.4 4.7 6.2 7.2 7.1 4.5 3.7 3.4 10.6 ± 6.4 4.7 4.7 4.4 3.3 3.6 3.8 4.0 4.5 5.5 5.4 4.0 3,1 3.1 915 I 8.9 + 3.0 4.9 ± 3.1 945 975 4.4 ± 5.5 2.0 2.9 1.9 ± 3.2 1.9 4.0 1005 1 ),p(GeV/c) and t 1 (GeV/c) + ± + + + ± ± + ± ± + + ± + + + + ± + ± + + + + + I 2 0.007 -2.0 15.7 3.8 7.0 12.8 9.3 17.0 16.0 23.4 13.6 16.4 14.3 3.5 8.4 I + + + ± ± + 4 + t ± + + + 8.4 6.0 4.3 6.0 5.5 6.0 4.9 4.9 4.5 5.5 8.2 5.6 4.4 8.4 5.6 + 8.0 2 0.009 2.3 9.3 6.9 -0.8 7.2 4.1 10.8 14.8 14.8 2.5 5.8 7.6 -6.9 + 2.4 ± 5.7 + 4.5 ± 1.6 + 3.5 + 4.1 ± 6.9 + 4.4 ± 4.6 + 10.3 + 3.5 ± 5.1 ± 9.8 5.4 + 5.6 --------------------------------------------- ___ 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 I I 1 I I I I 22.4 29.9 30.0 44.8 44.8 60.6 1 74.2 I 94.5 1132.6 1133.3 I 83.0 I 54.8 I 27.7 I 11.5 1 14.5 1 2.5 I 1.7 I 2.0 + 12.3 + 6.8 ± 5.1 ± 5.7 ± 4.3 + 3.7 + 3.8 + 4.5 + 5.6 + 5.4 ± 4.5 + 4.2 ± 3.5 ± 2.5 ± 2.5 + 3.3 ± 2.8 + 1.5 23.9 4.3 27.3 41.0 36.3 29.4 46.8 65.2 76.6 90.2 44.4 19.6 19.3 2.2 8.3 1.4 2.4 2.2 P = 6.2 GEYt/ ± 17.3 107.0 ±176.4 4 7.2 12.1 4 9.0 ± 7.6 19.8 ± 7.7 - 7.4 10.3 - 6.4 ± 5.8 20.7 + 5.3 ± 4.8 20.8 T 4.9 ± 5.0 30.8 - 4.3 ± 5.8 44.5 ± 6.4 ± 6.1 52.5 ± 6.9 ± 6.8 42.2 + 6.5 + 5.0 37.1 + 5.5 + 7.3 15.5 + 4.5 ± 4.9 13.8 ± 4.5 ± 3.3 1.2 ± 1.6 + 3.1 8.0 + 4.8 ± 2.6 + 2.6 -2.0 t 4.0 + 2.2 M_ I 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 ± ± ± ± + ± ± + + ± + ± + 4.7 3.1 6.7 4.0 4.6 5.3 5.9 4.9 4.8 4.2 3.2 1.3 6.1 6.5 3,2 + 6.3 5.9 0.1 9.9 4.3 3.9 10.6 7.2 14.9 7.1 7.2 9.0 4.4 5.4 1.5 + + ± + ± + ± + ± ± + ± + ± 2.8 ± 1.9 + 4.9 8.6 4.3 4.7 2.6 2.8 4.5 5.7 3.1 3.3 4.4 5.6 2.9 3.0 3.4 3.8 P = 6.6 GE•L/C I 98.7 ± 44.1 1 44.5 ± 10.0 1 48.7 1 57.1 I 69.2 J 83.8 1113.9 1145.7 1151.1 I 96.9 1 59.2 1 30.9 1 16.9 I11.7 I 6.3 I 5.9 1.9 21.3 5.5 17.8 27.2 32.2 29.0 14.5 13.7 4.4 0.4 7.5 5.2 5.9 8.7 ± ± ± ± ± ± ± ± + + ± ± ± ± ± 7.5 7.4 5.7 4.8 5.3 6.1 6.6 5.2 3.6 3.6 3.1 2.8 1.7 2.2 6.3 27.4 33.2 49.2 52.7 44.9 42.6 84.3 94.6 89.8 75.7 37.7 18.2 8.7 6.2 5.2 7.2 6.4 + ± + + ± + ± ± ± + ± ± ± ± ± ± 30.2 15.9 11.3 10.7 6.9 5.5 7.2 7.7 6.9 6.8 4.9 3.5 3.2 3.2 2.4 4.3 3.9 84.6 30.6 29.0 21.8 18.1 31.8 38.3 57.7 41.7 27.5 20.1 6.7 3.9 9.9 1.2 4.3 5.8 t 49.0 ± 13.2 + 8.0 + 8.2 ± 6.6 + 5.4 + 4.8 + 6.9 + 7.8 + 4.6 + 4.1 + 4.1 + 2.9 + 3.6 + 3.2 - 4.3 + 6.4 Fig.17h 9.5 0.1 11.8 20.9 14.4 25.4 32.4 22.8 12.1 10.1 3.2 5.5 3.6 4.1 3.2 + ± ± ± + + + + + + ± + + + 8.5 3.6 8.6 5.7 5.6 5.5 5.0 5.9 5.6 3.3 3.7 3.7 2.3 3.0 6.4 14.2 8.6 6.0 11.6 13.8 13.6 15.6 21.8 9.9 9.7 2.6 0.6 0.9 + 11.2 ± 8.8 ± 5.1 ± 7.5 ± 4.1 + 4.3 ± 5.6 ± 5.0 + 3.8 + 4.3 + 3.7 + 2.0 ± 1.8 -97- d in pb/sr.MeV/c 0.001 I 0.003 ANALUM 1 -r = M 2 vs. m(MeV/c I P 20.7 27.5 30.9 39.6 43.8 54.3 59.3 83.0 105.2 97.0 69.0 41.1 20.7 12.6 6.6 *+ 5.5 + 4.7 + 4.6 ± 4.5 3.4 + 3.9 + 3.8 + 4.0 4. 4.2 ± 5.0 + 5.0 + 3.7 ± 2.9 + 3.0 ± 2.3 2.8 6.6 + -0.5 4 1.1 9.6 + 5.8 1C05 11.4 11.1 26.4 19.1 20.2 23.7 20.1 40.0 53.3 55.4 27.8 25.1 9.1 5.1 5.7 4.2 ),p(GeV/c) I 0.005 p = c;a arpvi6.6 t 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 2 7.4 6.4 5.4 5.8 4.2 4.1 4.3 4.7 4.5 5.8 5.6 5.5 3.8 2.6 3.2 2.9 = B and t. (GeV/c) I 0.007 2 0.009 GFY/G i 9.0 4.9 5.0 6.3 4.4 2.6 4.0 3.6 4.7 5.2 5.1 4.1 2.8 2.3 6.5 14.0 7.5 13.6 10.3 21.9 12.1 31.6 26.0 19.8 12.7 8.6 0.3 -4.0 4- 7.7 + 4.1 ± 4.1 - 2.4 4" 5.3 1.5 2.2 9.1 11.6 16.1 10.3 23.4 7.3 4.9 5.7 3.2 3.8 + 4.9 4- 1.9 - 4.4 ± 3.4 + 3.8 + 2.9 + 4.3 + 8.8 43.2 +4 3.8 3.4 2.6 ± 2.1 ± 1.1 + 0.5 + 4.9 + 10.1 + 4.0 + -3.3 ± 4.6 ± 2.6 4 -3.4 + 7.6 1.9 2.7 2.2 2.8 1.5 2.4 4.8 2.7 2.2 6.6 2.2 2.3 9.5 3.4 ± -2.7 + 2.1 ± -0.5 + 4.2 3.1 " 4.8 + 3.9 + 6.8 ± 4.7± 5.1 ± 0.3 + 1.7 0.6 + 3.2 4.9 2.0 1.6 2.0 1.4 3.5 3.1 2.3 1.9 2.7 3.7 1.4 3.1 -2.6 -0.1 1.2 3.6 5.1 1.0 9.9 1.7 -0.2 0.4 1.1 0.8 1.6 3.0.. 2.0 2.7 2.0 2.3 2.5 2.6 1.8 1.5 1.1 2.0 1.3 2.3 P = 6.2 GEL/C _ 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 16.4 32.6 38.8 37.6 643.5 I 60.5 I 75.2 1106.4 1129.1 1122.5 1 85.6 I 51.3 I 32.5 I 16.1 1 8.5 I 7.0 I 8.5 I 1.1 .M 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 I. 1 I 81.8 1 31.4 1, 53.0 I 56.4 1 72.9 1 90.1 1118.6 1159.7 1149.8 1106.1 1 64.8 I 29.5 I 21.4 I 12.1 I 7.8 1 6.0 1 4.1 I I I j I + 11.6 + 7.0 ± 5.7 + 5.7 - 4.4 + 3.7 4 3.8 4.7 4 ± 5.4 + 4.9 5.9 4 3.7 4 + 3.4 + 2.5 L1.7 ± 3.4 + 4.7 ± 1.2 44.5 0.9 17.7 28.6 30.5 25.1 45.5 52.8 62.3 57.0 41.1 17.1 14.9 7.3 5.5 2.7. 10.4 4.8 + 23.1 + 7.2 + 6.8 + 6.2 ± 5.4 ± 4.7 + 4.8 + 5.2 + 5.3 ± 5.3 4 4.4 ± 7.6 64.1 + 3.6 + 2.4 2.2 ± 5.7 + 3.4 10.8 15.0 9.0 16.0 14.5 26.5 29.1 36.1 34.4 22.8 5.0 12.7 4.6 3.8 + + + + 8.4 6.4 6.0 4.8 4+ .3 + 3.9 4+ 5.2 + 5.5 + 5.4 4 4.0 - 3.0 3.6 + 2.7 + 1.9 0.1 + 6.2 + 6.2 ± 8.0 8.4 + 14.5 + -0.3 7.8 14.4 4 10.6 ± 12.5 + 7.7 + 6.8 + 5.4 1.5 + 6.9 + 2.2 + 6.8 4.3 4.9 5.0 2.6 3.3 3.7 3.8 3.1 3.4 2.4 3.0 1.4 3.8 2.7 5.6 4.5 P = 6.6 GEVY/C + 39.6 4 9.0 + 7.8 + 7.6 ± 5.9 + 5.0 + 5.5 . 6.4 ± 6.5 5.1 + 3.5 + 3.3 + 3.0 4 2.5 1.7 ± - 1.9 ± 3.5 33.0 36.2 33.9 41.2 48.4 57.6 75.3 80.7 60.4 28.3 21.2 9.1 6.2 6.1 2.8 3.9 + 16.0 - 9.5 ± 9.4 + 6.6 + 6.0 ± 6.2 ± 6.9 + 6.5 ± 5.8 + 3.9 ± 3.4 ± 2.8 ± 2.5 2.1 ± 3.0 + 4.0 1.6 16.7 21.1 18.2 20.5 24.7 54.9 39.4 T 21.7 13.3 4.4 4.3 3.6 0.4 2.7 + + + + . + + + + 4 6.2 6.1 8.0 6.6 4.3 4.1 6.7 7.4 T 3.9 3.2 3.2 2.6 1.9 2.0 2.9 -- Fig.17 i 13.8 16.5 5.0 7.5 3.5 14.5 16.0 11.8 9.8 6.3 2.9 6.9 0.4 + 10.4 ± 6.6 - 6.7 ± 3.7 + 3.9 + 4.0 ± 3.6 ± 4.2 ± 4.2 + 2.3 + 2.7 ± 2.8 + 0.9 52.1 94.2 + ± ± ± + + ± ± ± ± + 4 + -98- TUNGSTEN -T = I _M 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 - 0.001 525 555 585 615 645 1 30.5 ± i 30.3 _ I 25.6 + I 35.8 1 48.4 + I 57.7 ± 1 66.9 ± 1 88.7 ± 1105.7 + 1101.3 + I 74.9 ± I 38.6 + I 27.3 + I 10.1 - 1 5.9 ± I 1.6+ 1 4.0 + I ] 10.1 + 1 44.8 ± 1 27.7 _ I 42.1 ± I 42.4 ± 1 62.2 + 675 1 79.3 + 705 735 765 795 825 1102.3 1130.6 1128.7 I 89.6 I 57.9 945 I + ± ± + + 855 I 23.3 + 885 I 12.5 + 915 I 12.0 ± 975 I 1005 I ,,Y M 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 in I pb/sr.MeV/c 2 vs. m(MeV/c2),p(GeV/c) and t, (GeV/c) I 0.003 l . 495 d 0 -3.9 ± 0.1 + 1.8 ± I 0.007 I 0.009 P = 5.80 GEVY/C 8.4 6.5 5.7 5.2 3.9 4.7 4.8 5.0 5.2 6.1 6.5 6.4 5.7 6.3 3.5 1.6 3.7 11.3 5.0 21.9 22.7 21.1 35.5 37.4 43.8 56.7 47.2 31.8 26.3 21.0 8.7 1.6 3.3 10.7 8.7 5.6 7.7 5.2 5.7 6.4 6.4 5.7 7.2 7.6 9.5 7.3 4.6 3.1 3.3 -0.6 12.0 6.7 1.2 3.8 11,5 7.4 7.8 4.5 7.5 3.8 3.4 5.1 6.2 5.8 27.0 29.8 29.5 29.0 18.4 7.1 6.6 6.9 5.9 2.6 6.6 4.9 22.8 16.1 -1.3 6.0 4.7 8.0 + IP 15.5 10.4 6.8 7.8 5.6 4.4 4.5 5.4 6.4 6.0 5.2 4.7 5.7 5.1 3.3 7.8 4.3 1.8 = 6.2 GFVC + 11.8 + 8.7 + 7.6 ± 6.8 + 5.4 ± 5.6 * 6.2 ± 6.9 ± 7.1 + 5.6 + 10.6 + 7.4 ± 13.7 + 2.3 + 3.2 0.9 + 10.9 10.9 + 7.7 16.2 + 9.4 17.4 - 5.4 10.3 + 5.0 23.8 + 4.3 13.7+ 5.2 29.4 + 6.9 30.8 + 6.6 18.1 + 5.0 17.6 + 5.5 9.8 + 4.1 2.0 _. 2.8 9.9 +9 6.4 5.2 10.9 32.7 36.0 18.7 42.7 49.5 71.8 68.6 42.2 24.0 9.0 3.6 2.2 -1.6 0.1 + 9.7 + P· = A.A 23.3 13.0 10.2 10.1 7.1 5.7 6.2 7.0 7.7 6.1 3.8 4.4 5.1 6.3 2.7 5.0 8.9 + 5.5 37.9 9.6 32.0 53.6 35.1 35.0 62.1 80.7 84.6 64.5 32.7 18.2 10.1 10.0 1.4 8.2 + 40.8 " 19.4 ± 11.1 + 13.8 ± 7.5 ± 6.6 ± 7.2 ± 8.3 + 8.2 ± 7.0 + 5.1 + 3.6 ± 5.1 + 5.2 + 1.6 ± 6.3 10.0 12.2 15.8 24.9 16.7 30.3 44.5 39.1 29.0 5.9 1.8 4.3 2.7 0.1 -1.0 ± 12.1 5.5 + 4.6 8.1 + 5.9 0.4 ± 6.2 9.4 + 5.3 1.1 + 5.9 6.7 + 4.2 8.1 + 5.0 24.5 + 4.7 3.3 + 5.5 22.9 ± 9.7 9.3 + 5.3 4.1 ± 3.7 6.8 6.1+ 4.8 ± 9.6 11.0 + 10.8 5.1 ± 3.2 2.6 ± 2.7 2.1 2.3 ± 2.2 ± 3.0 3.1 + 2.5 5.0 ± 4.2 3.1 + 5.5 8.7 + 3.4 8.3 ± 3.8 0.9 ± 13.4 7.5 + 4.2 2.7 2.8 9.2 + 4.8 + 7.7 5.2 9.5 -_ 32.4 + 23.9 I I 19.8 + 1 37.6 ± 1 47.7 + I 63.3 ± i[69.1 + I 80.6 + 1109.3 ± 1143.0 ± 1154.8 1106.7 ± I 52.6 ± I 31.6 ± 1 22.0 ± 1 6.5+ I 9.0 ± I 10.5 ± 1 0.005 2 8.9 7.0 _ 279.2 26.6 11.7 8.3 14.6 2.0 13.1 8.6 17.3 16.1 +242.7 ± 16.8 ± 6.1 ± 6.4 ± 5.4 + 4.0 + 4.6 ± 4.1 - 5.4 - 4.5 12.6 ± 5.2 + + ± + 2.5 4.8 3.2 2.7 7.0 7.7 5.8 2.4 3.4 - 7.1 10.5 + 10.3 6.3 ± 4.4 11.0 ± 6.0 + 8.1 ± 3.1 1.6 ± 3.2 ± 2.6 14.3 + 9.4 5.4 4.0 3.8 3.5 2.9 6.0 1.2 + Fig .17j 5.9 4.5 4.5 5.5 5.8 2.9 4.1 6.8 8.6 3.2 2.6 1.9 2.0 4.6 ±+ 4.0 + 3.3 + 2.3 ± 3.9 ± 5.7 4.6 + 9.2 6.0 + 6.0 ---- 12.1 ± ± ± + ± ± 3.5 C•VuIr 10.7 7.6 8.1 9.8 5.1 5.3 -3.3 7.2 -0.3 2.9 5.3 6.1 -0.5 8.4 2.0 8.7 -0.4 ~--·- 9.9 4.1 3.6 6.6 2.7 2.7 3.4 3.4 3.9 + 3.2 2.9 + 2.9 2.3 1.4 ± 0.8 ± 1.7 1.2 ±+ 2.3 1.6 ± 1.9 11.0 -3.6 2.1 9.9 4.7 2.3 -0.9 14.2 + ± ± ± + + + ±+ -99- GOLD - t -r = I in pb/sr.eV/c 2 I 0.001 I 21.8 I 22.7 1 37.3 I 40.0 I 38.0 1 54.9 1 64.8 1 89.3 1102.6 1105.1 I 67.9 I 39.6 I 25.9 I 11.6 | 15.7 I 9.4 I 0.1 I 8 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 1 M m• I 7.5 5.8 6.0 5.2 3.4 4.3 4.3 4.9 5.3 6.6 6.5 6.4 5.3 6.1 . 5.0 ± 4.0 ± 2.4 ± ± ± 4 ± + ± ± ± ± ± + + ± I 35.4 I 35.5 1 34.0 I 37.1 i 46.6 1 64.6 1 88a. 1103.3 1134.9 1132.4 1 92.3 I 50.9 I 26.1 I 12.6 1 15.6 1 -2.1 I 0.1 i 5.3 19.1 9.6 6.8 7.2 5,5 4.2 4.2 4,9 6.6 6.1 5.5 4.7 5.5 4.9 3.7 7.7 4.1 3.1 _P 9.9 9.7 6.1 7.6 4.4 4.6 5.4 6.0 5.7 7.3 7.4 9.3 7.6 5.4 3.0 4.5 6.8 32.0 30.3 27.3 26.6 29.3 20.8 40.9 46.3 78.1 74.4 1 31.3 19.2 6.9 10.6 4.2 3.2 4.0 3.7 + + ± ± ± ± . ± ± ± ± ± . ± + ± ± P + 23.7 ± 16.2 + 10.0 ± 6.9 ± 6.2 ± 5.1 ± 5.0 ± 5.6 ± 6.7 ± 7.3 5.3 + 10.0 ± 7.4 ± 13.4 + 3.1 ± 5.2 + 4.4 + 3.7 I 1 56.5 ± I 54.8 1 61.1 1 90.4 1110.2 ± ± ± ± 735 1160.8 + 765 1155.7 + 795 I 96.9 ± 825 I 57.9 ± 855 i 37.7 + 885 I 27.9 ± 915 I 9.2 + 945 I 9.2 + 975 1 4.0 ± 1005 I 3.1 + 10.3 9.5 6.7 5.3 5.5 6.5 7.0 5.7 4.1 4.7 5.5 6.2 2.8 2.9 3.8 10.9 28.9 37.6 36.8 49.2 70.7 77.7 72.3 42.5 34.1 16.3 8.2 6.3 6.0 + + + + ± + + ± " + ± + + + 5.9 + 0.005 - 18.6 10.5 12.1 7.4 6.6 6.6 7.2 7.1 5.8 5.2 3.6 4.5 4.2 3.1 and tL (GeV/c) 0.007 i I 2 0.009 = 5.8 GEVYF 4.2 ± 7.7 7.5 + 6.8 7.3 + 4.6 0.3 ± 5.4 13.1 + 5.1 11.3 + 3.1 24.5 + 4.4 15.3 + 5.2 25.1 ± 5.9 26.5 ± 6.9 29.8 7.6 T 23.9 ± 6.8 12.6 - 5.1 -1.1 ± 2.2 -5.7 3.4 4.8 8.7 10.3 -0.7 6.5 2.6 15.9 5.2 13.8 8.0 3.7 + ± ± ± ± + ± ± ± + ± 8.0 3.8 4.7 6.7 4.9 4.3 4 3.5 4.2 4 4.1 5.2 7.1 3.9 3.3 4.9 3.5 6.3 1.9 1.8 2.7 3.2 8.9 7.5 8.0 0.3 2.3 + ± ± ± ± . ± ± ± + ± ± 4.9 + = 6.2 fEV/C -2*.4 13.1 20.4 18.6 11.0 22.2 23.1 32.6 30.2 18.0 6.8 11.5 6.5 8.8 7,8 8.9 5.5 4.3 4.0 5,1 6.3 6.6 4.8 4.3 4.3 6.8 -2.8 + 5.5 P = • _ t 495 I 525 I 19.7 + 23.2 555 1 36.3 + 12.5 585 615 645 675 705 7.7 20.2 24.6 22.7 10.9 26.2 31.9 30.3 47.8 47.3 32.5 32.3 26.5 16.0 2.8 6.3 5.4 m(MeV/c2),p(GeV/c) 1 0.003 _ 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 vs. A.A 4.8 27.0 11.2 15.1 24.3 31.1 35.7 30.1 20.6 14.2 8.9 0.9 7.42.5 =FVIC . 8.9 9,1 7.7 8,1 5.5 4.8 5.5 7.2 4.7 4.4 4.9 2.0 4*7 5.9 6.0 Fig. 17 k 8.3 6.7 4.9 12.6 -1.9 12.1 5.0 15.4 17.7 8.1 6.6 3.8 5.9 2.2 19.6 2.0 -2.6 4.3 0.5 1.8 1.9 10.4 3.1 3.3 3.0 2.4 0.2 1.9 5.3 + ± ± 4 _+ ± ± ± + + + + 2.8 7.2 2.4 2.4 1.4 1.3 4.2 3.1 2.6 2.2 2.0 5.0 2.4 8.8 8.3 6.6 . 6.2 -1.1 ± 5.4+ 9.2 4.7 ± 4.5 1.6 ± 5.4 6.7 +± 3.9 3.7 -0.2 ±t 7.1 ± 4.9 3.9 ± 5.2 2.5 ± 2.9 2.6 -1.1 ± 1.7 +± 96.4 6.4 3.9 3.4 4.3 1.8 2.6 2.0 2.4 2.9 2.4 4.8 2.4 +4 9.2 4.8 + 5.0 2: 4.9 + 2.8 3.8 4 4+ 3.3 + 4.5 4. 4.5 4.7 + 4. 2.8 ± 3.0 4+ 3.1 4+ 2.5 4+ 15.2 4- 6.9 2.3 3.9 1.7 2.9 1.9 3.0 6.6 3.2 3.7 6.8 2.0 . 4.4 7.4 7.8 11.3 9.5 7.6 11.3 17,8 11.1 9.8 6.3 -0.6 69.2 3.0 ± 2.5 -100- LEAD -L- -r = I I • • in i 0.001 _ .. 495 1 33.4 - 4.9 525 1 30.5 ± 4.2 555 1 35.7 + 4.8 585 37.1 ± 4.6 3 615 ) 42.3 ± 645 I 46.4 + 675 705 735 765 795 825 855 885 915 945 975 1005 M 64.0 I 79.9 1106.5 1106.1 I 69.9 1 40.6 I 25.0 1 12.2 ) 6.1 1 2.6 I 11.7 I 3.7 3.3 3.6 3.7 4.1 4.5 5.4 5.3 4.9 4.2 4.4 3.7 4 4.5 + 4.5 + 3.9 ± + 2 ÷ + + + + 2 pb/sr.MeV/c2 vs. m(MeV/c2 ),p(GeV/c) and t. (GeV/c)2 I 0.003 I 0.005 0.007 P = 5.8 GFY/C 6.2 + 5.1. 10.3 . 4.5 0.7 1 2.8 ± 4.5 3.1 16.5 . 5.2 19.2 + 4.3 11.3 + 6.1 1.2.2 + 4.4 1.4 2.0 1 4.4 3.3 23.4 35.6 40.3 57.0 43.4 25.6 16.2 16.9 6.5 9.0 17.0 13.5 29.3 16.3 7.7 10.0 5.6 2.2 4.2 3.4 -0.1 1 4.0 ± 14.4 ÷ 13.4 + 10.5 + 13.5 ÷ 4.9 + 3.92 7.1 + 6.8 + 4.0 2.8 4.1 3.2 4.5 9.2 2.6 3.2 7.2 9.6 7.0 ± ,7.6 ± 24.1 1 7.1 5.7 8.8 1 4.7 5.1 ± + 4.0 4.9 .5.3 + 4.9 + 6.0 ± 6.3 - 5.5 + 5.8 ± 3.1 4.7 + 0.1 + 3.4 7.1 I ± ÷ + + 2÷ 4 ÷ ± +_ 2.5 3.6 4.1 5.1 5.3 4.9 3.9 2.8 2.5 4.7 3.5 3.6 1 2.9 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945, 975 1005 1.7 0.5 + 2.5 0.5 0.9 + 0.4 + 0.9 1.8 2.9 + 2.0 1.1 4.3 2.9 4.1 6.2 15.0 2.1 + 1.3 + 2.7 + 3.8 1 2.3 + 2.9 + 11.4 + 1.6 4.4 1 6.3 2.8 + -1.8 + 0.8 . 0.6 + 1.2 .. 4.3 + 2.4 1 1.2 _ 2.4 + 2.7 4.62 -0.0 + 3.1 + 2.0 4.1 1.6 1.6 1.1 1.2 2.3 2.3 2.0 1.8 2.5 2.6 2.7 P = 6.2 GEV/CY 1 . _ 1 I 38.7 + 20.4 28.0 + 7.2 I 45.4 2 6.3 1 56.4 + 6.8 1,59.5 + 5.7 1 88.3 + 4.8 1121.2 + 5.2 1148.6 2 5.8 1152.7 ± 6.2 1102.9 + 5.0 I 62.9 + 3.6 28.8 + 3.7 1 18.4 + 3.7 I 11.2 4,.4 5.7 _ 1.9 1 3.2 + 2.4 1 9.5 ± 5.8 0.009 -6.1 + 12.3 495 I 29.5 + 10.1 -7.9 + 22.4 141.1 ±168.4 -23.9 + 525 1 40.2 1 6.7 5.0 + 6.2 12.4 . 6.9 3.1 2 555 1 33.1 . 4.9 20.5 + 6.4 12.7 + 5.1 4.0 + 585 1 46.2 2 5.3 25.7T 6.5 13.2 + 6.4 2.6 1 615 1 48.5 + 4.9 15.0 + 5.3 15.8 + 4.3 10.8 645 I 65.8 + 3.8 26.4 1+ 4.7 9.5 + 3.7 0.2 675 I 83.6 + 3.7 38.42 4.5 16.6 + 3.4 10.0 ÷ 705. 99.0 4.4 47.4 . 5.0 28.6 +- 4.5 10.7 + 4 735 1137.6 _ 6.2 61.0 - 5.3 27.5 - 5.0 13.2 1 765 1137.4 . 5.3 65.3 + 5.8 20.2 + 5.0 10.0 + 795 I 88.3 + 4.7 39.7 + 4.7 20.5 + 4.3 7.1 + 825 I 54.9 + 4.2 20.02 7.8 1.6 + 3.6 5.8 + 855 I 30.8 4.8 11.9 4.7 14.1 4. .1 6.1 885 I 15.9 + 4.0 6.2 + 7.7 3.9 + 3.2 3.5 + 915 1 10.0 + 2.7 6.0 ± 3.5 0.8 + 945 3.6 + 4.9 2.3 1 2.4 975 I 4.4 + 3.2 3.0 + 3.3 2.4 + 1005 2.7 . 1.9 0.1 + 6.6 -------------------------------------------------------------1 1 14.6 17.8 44.2 13.3 37.7 49.1 67.1 73.5 72.1 54.5 25.7 14.8 11.7 5.9 2.2 9.3 4.4 + 15.7 2 11.5 1 8.7 + 8.5 + 6.6 + 5.9 + 6.3 + 6.6 + 6.3 ÷ 5.6 2 4.1 " 3.0 ± 4.4 ÷ 3.4 _ 1.8 + 5.8 + 4.5 95.9 3.5 2.3 3.2 4.2 2.5 3.0 3.2 3.7 3.1 3.7 2.0 3.4 2.1 1.6 2.4 = 6,6 GFYV/C 8.2 23.9 20.4 11.7 5.7 18.0 28.7 36.0 20.7 18.9 14.0 2.1 -1.9 4.0 " 10.6 1 8.1 + 5.9 - 5.7 t 4.5 ± 4.4 ± 4.1 ± 5.0 ± 5.9 & 4.0 ± 3.6 + 3.5 + 2.8 + 3.1 3.7 + 5.4 Fig. 171 14.8 ± 23.1 14.0 + 7.0 1.5 ± 3.6 -4.4 + 7.0 2.9 + 2.9 9.8 - 5.0 6.6 + 3.2 11.8. 3.0 10.8 + 4.2 4.4, 4.0 3.8 + 2.3 1.1 2 3.0 -3.5 2 7.0 2.8 + 1.9 4.2 + 6.1 7.0 4.6 4 -0.6 + 2.0 4.4 + 3.1 1.6 + 2.6 5.0 + 2.1 2.7 + 1.9 2.4 2 1.7 5.0 _ 1.7 2.4 2 2.2 0.7 _ 1.7 1.0 2 1.9 3.1 2 2.7 2.2 + 2.7 2.5 2 2.0 -6.0 + 12.0 -101- URANIUM URANIUM -f = I S 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 11005 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945. 975 1005 .M 495 525 555 585 615 645 675 705 735 765 795 825 855 885 915 945 975 1005 dA in pb/sr.MeV/c 2 vs. m(MeV/c2 ),p(GeV/c) and t. (GeV/c)2 A d =1'0.001 I 0.003 I 0.005 I 0.007 1 0.009 I I 14.46 1 21.3 I 39.7 I 36.0 I 44.3 I 54.1 1 59.9 I 78.2 I 97.7 I 93.2 I 68.8 I 41.8 I 18.3 1 7.8 I 3.6 I 2.9 1 2.6 5.4 + 4.5 ± 5.0 ± 4.3 + 3.3 + 3.8 ± 3.5 ± 3.5 ± 3.7 + 4.3 + 4.6 4 4.8 ± 4.0 + 4.6 - 3.6 ± 2.9 ± 3.1 23.5 8.2 14.7 16.7 18.8 22.1 21.2 41.1 48.3 43.5 24.9 15.2 8.1 6.3 1.1 2.2 2.8 + + ± ± t ± ± + ± ± ± ± ± + ± ± 9.3 6.5 3.9 5.7 4.Z 3.7 3.8 4.3 3.8 4.9 5.3 6.0 3.4 3.5 2.1 3.1 3.9 P = 5-8 GE-YLC--3.6 + 5.6 -3.3 12.3 4 6.5 3.8 0.6 7.7 + 3.5 10.0 + 5.7 2.1 6.4 4 3.3 7.1 13.7 + 2.6 -0.7 15.9 + 3.0 3.6 14.0 + 3.6 3.9 24.2 . 3.8 11.8 22.6 + 4.5 9.6 8.9 t 3.9 11.8 13.3 . 4.1 9.4 6.3 . 2.8 7.1 1.1 + 2.2 0.9 1.4 + 1.8 + 2.9 3.6 + 4 ± ± , + + ± ± + + ± ± ± 4.7 2.6 2.4 3.3 2.9 3.2 2.0 2.7 2.3 3.4 5.1 3.3 3.4 1.7 1.3 ± 2.6 5.4+ 6.3 ± 4.7 + 3.8 + 4.9 ± 3.0 3.7 2.5 2.2 2.2 2.1 2.7 2.2 2.4 1.8 3.8 0.8 1.9 + ± ± + ± 4 ± ± ± 1.2 1.1 1.6 0.7 1.6 2.3 1.9 2.4 9.5 2.0 2.5 0.8 -1.1 1.3 -0.2 0.7 1.8 2.5 0.4 3.9 3.0 4.3 -0.6 1.3 1.5 ± ± ± ± . + ± + ± ± ± ± ± ± 1.1 2.9 0.9 0.7 0.6 0.6 1.6 1.2 1.7 1.3 2.0 3.2 1.7 2.9 4.2 1.9 1.8 1.3 1.5 1.0 1.1 3.0 + + 4 ± ± ± _ ± 0.8 0.7 0.5 0.9 ± ± ± ± 4.1 2.3 1.2 1.5 1.1 0.9 1.0 0.9 1.6 1.4 1.5 1. 1 1.8 1.6 1.9 1.6 1.0 2.5 2.5 7.0 6.6 5.1 3.1 3.4 I I. M I 16.4 1 42.2 1 34.9 1 40.7 46-.1 1 66.0 I 78.0 1103.6 1125.2 1129.8 1 83.9 I 47.4 I 31.8 21.8 I 6.1 ± 12.5 ± 8.2 + 5.6 ± 6.0 ± 4.7 ± 3.7 + 3.5 +± 4.2 + 5.0 ± 4.4 + 4.7 ± 3.3 ± 4.7 ± 4.6 2.0 S1.9 + 6.3 1 3.3 ± 4.8 1.8 1 1.2 I 56.7 ± 33.4 9.8 7.5 7.2 5.9 I 82.0 ± 4.6 1117.3 + 5.0 1150.0 ± 5.6 1150.5 ± 5.8 1 99.6 + 4.4 61.9 ± 3.0 1 29.5 ± 3.2 i 15.8 ± 3.4 15.8 ± 54113 I 5.4± 1.8 5.1 ± 3.2 2.7 1.4 ± 1 34.0 ± 1 40.7 ± I 41.7 ± 6' 68.0 ± 22.3 + 16.7 18.9 _9 11.0 16.8 ± 7.0 26.5 ± 5.7 21.9 ± 4. 8 20.4 ± 4.2 33.9 + 4.0 44.3 ± 4.4 54.1 ± 4.5 60.4 ± 4.7 32.6 ± 3.7 18.6 ± 7.7 7.3 ± 5.0 10.6 + 10.1 1.6 + 1.9 3.8 + 4.3 2.6 ± 53.1 29.3 30.2 15.3 31.2 37.7 57.5 70.8 70.6 43.9 22.1 16.3 7.2 8.5 5.0 3.2 2.0 4.0 4.6 5.5 19.3 12.2 11.8 22.5 24.0 23.3 18.5 9.7 7.7 2.5 4.2 1.9 0.1 6.6 4.5 5.3 4.7 3.6 2.7 3.9 4.2 4.4 3.2 3.3 2.8 2.5 3.4 3.7 5.4 4.4 ±. 7.8 + 9.2 ± 2.3 ± 7.3 + 10.0 0.4 ± 1.6 + 1.1 + 2.2 3.7 P = 6.6 GEYV/C . . P = 6*2 GFYV/ 40.0 16.5 8.8 7.7 5.8 5.2 5.3 6.0 5.6 4.5 3.2 2.5 3.6 4.5 2.7 4.0 4.0 28.4 20.6 4.1 12.7 5.1 18.4 18.1 31.1 22.7 14.2 7.3 7.7 7.4 3.3 0.4 0.8 26.1 10.0 4.1 5.7 5.5 4.1 3.3 4.4 5.3 3.1 2.6 3.2 3.3 2.6 3.3 1.6 Fig. 17 m 4.5 7.6 6.3 5.5 5.4 7.8 8.9 6.7 4.8 2.2 -0.3 2.3 1.0 0.9 3.8 + + ± + ± ± ±4 + . + ± ± ± + 5.1 4.2 5.3 3.0 3.5 2.5 2.3 3.0 3.0 1.6 1.6 3.0 1.2 1.9 7.7 1.9 ± -102- O o + 5555 +1 + + a +1 +1 +1-A 80800 .1 +1 +1 N 3 d +I k r bD ., "• .. eo·u rt· lu O 3 d ra ~Pi o~ j 6 w OOA a 0r - A 0- ~o M 0~ 0 MOOa 0000- Co *LU_ -103- < ) ) ) L) LW OI + (N II (Iiv43_-) SNIiav -104- ____ tf U ' 0 C II C U P-4 P.-o4 o Ln u -4 N N O w 0 LA oi o I4- 0 '0 '-4 -- -4 , l mO t) m'. N .0 1--4 -4 LO LA rO NN 0. CN N Ll 4 0o• 0 N \0 (INO NW CU -4 to In) 0 LA td) 0 0 1) t1 NO LA N to t) toV) (0 0 r, 0 N to) ' -4 -4 -4 -4 LA• -4 \rN 04N NN-4 0 CO ~ \0 0 - m' 000 -t 0 0O " -c 0 LO --4 N +1 +1 +1 +1 +1+ +1 +1 +1 +1 - -q N +1 +1+1 +1 +1+ r e +I+1 +I +I N S-4 *,U N ' +I +I + -4 r-4 0 0 4 +l + 0 O o + N-- N--- 00c *0 O1 I -4 +1 + S+ - to NO 0 --4 + +1 +1 +1 +1 + LA O0 CO LI 0 --- \ to 0 0'. 0 Ln L to Ln N NO SU I0 to N- N N CO \0 C• C) 0 0 '0'0LAN N 0 LA 0 LA C) 00 tl* tO -4 :T N -4 M N N CO LA \0 ID t 0 NC N N4 '0 \0 N m N to) N " N rN to) \0 -4 N -q m LA C. N LA Nto -4 al roo a par u N +I + N " Ln +I 'L )0O O 0 CO 4• N " +-4 N o) Cd) LA \0 +i +I +I+ 0 0 +-I -N4 14 wO LA N- 1-4 ~+I+ +- + N - C S N) NNl tO) r-4 \0 N 4 + -r n '0 N1+ C LA " 0' tAn 0 Nl + m' N m' m' C-I U C CU 0-. --4 0'. LA N +I N -- I 0 o N Cd. rN V) NI 0 +1 +1 +1 +1 c4 r-4 to '0 - * 0 L 0 N M N+ C N 'D LA N+ +) + LA) O N o 0m fo) 0m -4-4 -4 0 N N+ \'O00C C' to. m' '. \0 \0 N M' N " \) \0 ' + LA CO N 0 N M' N -I r-4 Ný -4 0 " to) tr N+1 +1+14 N NO NO '-4 + " -44 s N, - 0 + 0'. 0 - t +1 +1 +1 +1 LA '0 N CO N '- LA~ '0r NO3 +1+ +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 LA to 0 L N N N- to CU~ M LA LA LA 0 N '0O 0 L L 0 LA N 0 * LA LA Ln* '0 '0 '0 '0 *d t* to LL v nl~ 2 'z~ >% *, -4·- a . E. - J4·- ,•1 4) cO .r4 [- ___ o4 0 • LA Ln N r-4 + +1 + \0 +1 C4 c o N '0 C CU4 -4 ~ +1+I+1+1+1+1 t-) m Ln " r-4 404 z ' +1+1+1+1+1I+1+1+1+1+1+1+1+1 1:44 CO o '0 0 u '-4 -4 0 CLD --- m 4) -4 aC CU k= c% E d4C CL -105- -~ 2: C II~ -o0 .. 4 + c i I i i I I I i J I -~ Ml Iti E "•o' 'IL)" L.Jn u 2 U' Ef 0 L a4 iv LO Lo LL 0 LO a) *1= I I Lr) 1 ....... 0 0 0 0 0 [oalonu:jA L q11 0 0 0 0 0 o0-4p PV i L A0N 0000000 1 | 0 -106- d••eoo / A3 2 abt 28C (GeV/c)" atom DESY-MIT DATA o DESY-MIT FIT 3 260 1 i C I1 -T 24CI. 220I. I3 200I. 1 180 4.- A 1 tk Be I C , I Ti Cu Fig. 22 , .I JV AgCd In . .7 I-' TW AuPbU -107- C U) e wan I S-4- S..(a 00 = = II mME 0 II **t O• :O*-OOU -- X '- t 0 (0 4-) CJ (J. SCn)(n ro I II Oa EU 4- CC *-0 I II C 4to * l • 3 n 4-)E--I. 44-' W E*r l Qa- t_ ECJ -oO oS- 0 S. O I 0 0c O'C 0 O O CO > U C4-4-)0 -)j.3,i0 c 00 AC cUI,-4 >,I cn V)4- M V) S- . , 0 0 0a--4- 4A Ci C\J (\j Coj II II II 00 0 C)> L ca O (Ar- I V G NI icr U 0 +1 0000 co CO C) C) C) CO C) S,- .O C) e4C) +I +1 +I +1 +1 +1 N- C( Y) - + 1 1N C 0 C"Y C) x C_ U- co -•o h--o" ~C) ,-- _ CU, • ca < ,---13 C• _. 0 N Cz MI- " • ) "C) c.)C_) (m ca ( o c LJ 0 -J -j 0C C)4-)-l ,ai" 00. -j LU.. w J LL >- )w -j w I -- . , o ,LL,, ( -r.P. I