From the nucleus to the quarks
Roy J. Holt
Achievements and Future Directions in Subatomic Physics:
A Workshop in honor of Tony Thomas’ 60th birthday
Adelaide
15-19 February 2010
Tony’s perspective (ca. 1977)
Happy Birthday!
Courtesy of J. Carlson
Argonne National Laboratory
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The Deuteron has an Extraordinary Role
in Nuclear Physics
Hadronic
Probes
Nucleon-Nucleon
Models
Subnucleonic
Effects
Standard
Model
Neutron
Target
Argonne National Laboratory
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Tony’s 1977 letter on pion-deuteron scattering
“It [t20] is a very interesting quantity to measure …”
Argonne National Laboratory
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Scattering from aligned Deuterons
Spin 1 nucleus:
MS = 1
MS=1, -1
MS = 0
MS=0
MS =-1
Argonne National Laboratory
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Los Alamos Meson Physics Facility (LAMPF)
Series of three
pion-deuteron
scattering
experiments at
LAMPF
•Exp. 388 (LEP)
•Exp. 483 (LEP)
•Exp. 673 (P3)
Argonne National Laboratory
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Issues in Pion-Deuteron Elastic Scattering (ca. 1982)

Pion Absorption

– Afnan, Thomas,…
D



p,r
d
Exact three-body calculations
Relativistic
Include absorption
–
–
–
–
–
–
Dibaryon Resonances??
Rinat, Thomas et al.
Giraud et al
Blankleider and Afnan
Betz and Lee
Lee and Matsuyama
Garcilazo
D
d
1D , 3F ,
2
3
…
Argonne National Laboratory
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Polarization in Pion-Deuteron Elastic Scattering
The LAMPF Experiments
First polarization experiments in pion-deuteron scattering
R. J. Holt et al, PRL 43 (1979) 1229
R. J. Holt et al, PRL 47 (1981) 472
E. Ungricht et al, PRL 52 (1984) 333
Argonne National Laboratory
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Argonne National Laboratory
1983
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Pion-Deuteron Scattering Puzzle
Blankleider & Afnan
Betz & Lee
Fayard et al
Rinat et al
Garcilazo
Jennings & Rinat, NP A (1988)
Calculations that don’t include pion absorption agree best with the data!!
Confirmed by TRIUMF data: G. Smith et al, PRC 38 (1988) 251.
E. Ungricht et al, PRC 31 (1985) 934
Argonne National Laboratory
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Elastic Scattering from the Deuteron
Electron-deuteron scattering
Measure another quantity:
Scatter from aligned deuterons
e’
q=pe-pe’
d
MS=1, -1
d’
MS=0
Cross section depends on three
electromagnetic form factors:
Argonne National Laboratory
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Issues in Electron-Deuteron Elastic Scattering

Meson-Exchange Models
–
–

Wiringa, Schiavilla, et al.
Chung, Coester, Polyzou, Hummel, Tjon,
Phillips, Wallace, Gross, van Orden, et al.
QCD Inspired Models
–
Reduced Nuclear Amplitudes
•
–
Brodsky, Chertok, Hiller, Ji
Constituent Counting Rule
•
Brodsky, Farrar, LePage, Matveev et al
Argonne National Laboratory
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First t20 Experiment in Electron-Deuteron Scattering
First experiment in the South Hall at MIT-Bates
M. E. Schulze et al., PRL 52 (1984)
Argonne National Laboratory
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Polarized Deuterium Gas Target in the VEPP-3 Electron Storage Ring
Argonne-Novosibirsk Collaboration
2 GeV
200 mA
• First use of a storage cell for polarized gas targets in a storage ring
• Proof of principle for HERMES: DESY PRC
R. Gilman et al., PRL 65 (1990) 1733
Argonne National Laboratory
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Polarized Deuterium Gas Target in VEPP-3
Last published T20 measurement in e-d scattering!
D. Nikolenko et al, PRL 90 (2003)
Argonne National Laboratory
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World’s Data for Electron-Deuteron Scattering
Argonne National Laboratory
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Technology led to worldwide programs
Storage Cells in
Storage Rings
Neutron and
Deuteron
Polarimeters
Laser-Driven
Target
NIKHEF
LAMPF
MIT-Bates
SIN/PSI
TRIUMF
Jefferson
Lab
HERMES at
DESY
Novosibirsk
IUCF Cooler
Argonne
Argonne National Laboratory
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Two photon exchange in e-p elastic scattering
Rosenbluth data
Golden mode: positron and
electron elastic scattering from
the proton
Polarization transfer data
Three new experiments:
• BINP Novosibirsk – internal target
P. G. Blunden et al, PRC 72 (2005) 034612
A.V. Afanasev et al, PRD 72 (2005) 013008
J. Arrington et al, PRC 76 (2007) 035205
J. Carlson, M. Vanderhaeghen, Annu. Rev. Nucl.
Part. Sci. 57 (2007) 171
• JLab Hall B – LH2 target, CLAS
• DESY (OLYMPUS) - internal target
Argonne National Laboratory
Courtesy of W. Melnitchouk
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Very preliminary Novosibirsk data
e+-p/e-- p cross section ratio
J. Arrington, L. M. Barkov, V. F. Dmitriev, V. V. Gauzshtajn, R. A Golovin, A. V. Gramolinv,
R. J. Holt, V. V. Kaminsky, B. A. Lazarenko, S. I . Mishnev, N. Yu. Muchnoi, D. M. Nikolenko,
A. V. Osipov, I. A. Rachek, R. Sh. Sadykov, Yu. V. Shestakov, V. N. Stibunov, H. de Vries,
S. A. Zevakov, V. N. Zhilich ----- ANL, BINP, INP TPU, NIKHEF
Argonne National Laboratory
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Fast forward – Jefferson Lab
Argonne National Laboratory
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Deep Inelastic Scattering and Structure Functions
leptonic
Parton model:
hadronic

Proton structure function:

Neutron structure function (isospin
symmetry):

Ratio:

Nachtmann inequality:

Focus on high x:
Argonne National Laboratory
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The Neutron Structure Function at high x
SU(6) symmetry
pQCD
Scalar di-quark
Reviews: N. Isgur, PRD 59 (1999),
S Brodsky et al NP B441 (1995),
W. Melnitchouk and A. Thomas PL B377 (1996) 11.
Argonne National Laboratory
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Extractions with modern deuteron wave functions
The ratio at high x has a strong dependence on deuteron structure.
J. Arrington et al, J. Phys. G 36 (2009)
• Lorentz invariant convolution relation
• Light front with null plane kinematics
Argonne National Laboratory
Courtesy of J. Arrington
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Nuclear Physicists’ Approach to F2n
 Problems:
– The proton experiments are difficult and costly.
– The deuteron experiments present extraction complications.
 Nuclear physicists’ solution: Add another nucleon.
I. Afnan et al, PRC 68 (2003)
Argonne National Laboratory
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Ratio of 3He, 3H

JLab E12-06-118
Measure F2’s and form ratios:
I. Afnan et al, PRC 68 (2003)

Form “super-ratio”, r, then
where

Theoretically,
Argonne National Laboratory
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E12-06-118 Projected Results
• JLab E12-06-118, G. Petratos, J. Gomez, R. J. Holt, R. Ransome et al
Argonne National Laboratory
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Tritium target design must pass safety hurdle at JLab
Tritium Target Task Force
E. J. Beise (U. of Maryland)
B. Brajuskovic (Argonne)
R. J. Holt (Argonne)
W. Korsch (U. of Kentucky)
D. Meekins (JLab)
T. O’Connor (Argonne)
G. G. Petratos (Kent State U.)
R. Ransome (Rutgers U.)
P. Solvignon (JLab)
B. Wojtsekhowski (JLab)
Review: June 2010
Argonne National Laboratory
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Tritium Targets at Electron Accelerators
Lab
Year
Quantity
(kCi)
Thickness
(g/cm2)
Current
(mA)
Current x
thickness
(mA-g/cm2)
Safe FOM
(mAg/cm2/kCi)
Stanford
HEPL
1963
25
0.8
1
0.8
0.03
MIT-Bates
1982
180
0.3
20
6.0
0.03
Saclay
1985
10
1.1
15
16.0
1.6
JLab
201?
1.6
0.13
30
3.9
2.4
JLab also has a huge spectrometer acceptance advantage, eg. SBS
Argonne National Laboratory
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Summary
 Tony and colleagues have had a profound influence on experimental nuclear
physics.
 Pion- and electron-deuteron scattering drove polarization technology.
 Development of the polarization technology has been extraordinarily fruitful
– HERMES, MIT-Bates, Novosibirsk, NIKHEF, JLab, ...
 Latest internal target experiment: best evidence for 2-photon exchange
 Scientific stage being set at JLab for d/u ratio measurement using polarization
in isospin space: 3H/3He
Happy Birthday Tony!
Argonne National Laboratory
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