39th Symposium on Nuclear Physics
January 5th-8th 2016
Cocoyoc, Mexico.
List of Abstracts.
LIST OF ABSTRACTS. 39th SNP, 2016, Cocoyoc, Mexico.
Campaign of measurements to probe the good qualities of the new
array FARCOS for the multi-fragmentation spectroscopy.
Luis Acosta for the NEWCHIM collaboration.
Instituto de Física, Universidad Nacional Autónoma de México, A.P. 20-364, México
D. F. 01000, México
INFN-Sezione di Catania,Via Santa Sofía 64 I-95123 Catania, Italia.
During the last two year have been carried out four measurements related with real
physics case were the capabilities of FARCOS array were tested. In all this occasions,
FARCOS was coupled to the 4pi array CHIMERA, permanently placed at INFNLaboratori Nazionali del Sud, Catania. At the present situation, the FARCOS
demonstrator is formed by 6 telescopes from the originally 20 that will have the final
array. For all the experiments FARCOS was mounted in order to assist to CHIMERA in
the detection of Multiparticle fragmentation. Here will be presented the first results
obtained with the new array, probing its qualities. These preliminary results show the
effectivity of FARCOS telescopes supporting the construction of the whole array.
Near-barrier fusion of proton- and neutron-halo systems.
Elí F. Aguilera.
Departamento de Aceleradores, Instituto Nacional de Investigaciones Nucleares,
Apartado postal 18-1027, C.P. 11801, México, D.F., Mexico.
Previously reported data for fusion of the 8B + (58Ni,28Si) systems are critically
reviewed. The influence of breakup protons on the evaporation proton measurements for
the heavier system is found to be small at all energies except for the lowest one
measured, and corrections are made for this process. Possible model dependencies in the
deduced fusion cross sections are investigated using three different evaporation codes.
The data sets for the 58Ni and 28Si targets are shown to be consistent with each other
and with fusion enhancement up to energies that are greater than the Coulomb barrier
Vb(Ec.m. <Vb+ 1.5xħω). This limit corresponds to 6.2 MeV above the barrier for the
58Ni target. An important difference with the behavior of neutron-halo systems is thus
confirmed.
Study of 26Al production. Implications in nucleosynthesis and
cosmology.
Victoria Isabel Araujo Escalona.
Instituto de Física, Universidad Nacional Autónoma de México, A.P. 20-364, México
D. F. 01000, México.
Recent techniques and experimental methods have opened up new ways to explore
nuclear reactions relevant to nucleosynthesis near to stellar combustion temperatures. A
particular case is induced by deuterium, which represent a sensitive tool for
characterizing low concentrations of elements (as an isotope) in materials due to the
positive value Q (exothermic) in reactions (d, p) and (d,α). High energy particle
emerging from this reaction is then easily identifiable even with simple detection
configurations.
In this work we focus on the case of 26Al. Isotope actively associated with the process of
nucleosynthesis. Its presence in the solar system was unexpected until it was found in
the Allende meteorite. It is now understood that cosmic rays induce nuclear reactions to
produce materials. On Earth, this process is well known and is based on environmental
studies. So 26Al is not just the product of some high-metallicity star collapse.
For their study protocol is developed to quantify the number of deuterium hitting a
target of Si / Al, as a first step to determine the total cross section in the reaction
28
Si(d,α)26Al at very low energies of 2.6 MeV to 900 keV. Subsequently, it discussed as
an alternative method for determining 26Al production application technique of
accelerator mass spectrometry (AMS).
Nuclear Astrophysics Measurements with the TwinSol Radioactive
Beam Facility.
Dan Bardayan.
Physics Department. University of Notre Dame, IN 46556, USA.
The nucleosynthesis occurring in astrophysical explosions can be very different than
that which occurs in main sequence stars such as our sun. In fact, many of the
properties of explosive astrophysical events are determined by the nuclear physics of the
radioactive nuclei that power the explosion. At the University of Notre Dame TwinSol
radioactive beam separator, exotic nuclei of astrophysical interest are being produced
and studied in order to further our understanding of astrophysical explosions. In fact,
TwinSol was the first such device in the United States dedicated to radioactive beam
production. Recent studies of astrophysical interest using the device will be presented
along with plans for upcoming measurements.
Parity-Violating Asymmetries in the Interaction of Polarized Slow
Neutrons with Light Nuclei
Libertad Barrón Palos.
Instituto de Física, Universidad Nacional Autónoma de México, A.P. 20-364, México
D. F. 01000, México.
The measurement of very small parity-violating (PV) observables in few-nucleon
systems, where nuclear wave functions can be calculated, could help to improve our
understanding of the hadronic weak interaction (HWI), which remains enigmatic due to
the non pertubative nature of Quantum Chromodynamics at low energies. Of particular
interest are the strangeness-conserving nucleon-nucleon interactions, since their study
could shed light into some phenomena that have been observed in the strangenesschanging sector of the interaction and that cannot be explained in the framework of
existing theories. Additionally these interactions offer the possibility to study neutral
currents at low energies and constitute a probe for quark-quark correlations in nucleons.
The availability of very intense neutron sources allows the development of experiments
to measure PV effects in the 10^-8 level. I will describe measurements of this kind that
are being pursued at the Spallation Neutron Source of the Oak Ridge National
Laboratory.
Baryon spectroscopy in the unquenched quark model∗
Roelof Bijker
Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A.P. 70543, 04510 México D.F., Mexico
The constituent quark model (CQM) describes the nucleon as a system of three
constituent, or valence, quarks. Despite the successes of the CQM (e.g. masses,
electromagnetic coupling, magnetic moments), there is compelling evidence for the
presence of sea quarks from the measurement of the flavor asymmetry of the proton and
the socalled proton spin crisis. In this contribution, I present the unquenched quark
model as an extension of the CQM that includes the effects of sea quarks via a 3P0
quark-antiquark pair-creation mechanism. Particular attention is paid to the spin and
flavor content, magnetic moments, and β decays of baryons. as well as the strangeness
suppression in the proton.
The nuclear matrix elements of 0νββ decay and the NUMEN project at
INFN-LNS
Fracesco Cappuzzello.
Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via Santa Sofía 62
I-95123, Catania, Italia. 2Dipartimento di Fisica e Astronomia, Università di Catania,
Via Santa Sofia 64 I-95123, Catania, Italy.
The physics case of neutrino-less double beta decay and its tremendous implications on
particle physics, cosmology and fundamental physics will be introduced. In particular
the crucial aspect of the nuclear matrix elements entering in the expression of the half
life of this process will be deepened.
The novel idea of using heavy-ion induced reactions as tools for the determination of
these matrix elements will be then presented. The strengths and the limits of the
proposed methodology will be indicated. New data from MAGNEX facility at the
INFN-LNS laboratory give first evidences of the possibility to get quantitative results
about nuclear matrix elements from experiments. New results will be shown at the
Conference regarding the 40Ca(18O,18Ne)40Ar at 270 MeV incident energy.
Finally the NUMEN project of INFN and the proposed strategy to this research will be
sketched in the view of the upgrading of the INFN-LNS facilities.
Signatures of the Giant Pairing Vibration in the 14C and 15C nuclei
Manuela Cavallaro1., F. Cappuzzello1,2, D. Carbone1, M. Bondì1,2, C. Agodi1, F.
Azaiez3, A. Bonaccorso4, A. Cunsolo1, L. Fortunato5,6, A. Foti1,7, S. Franchoo3, E.
Khan3, R. Linares8, J. Lubian8, J.A. Scarpaci9, A. Vitturi5,6
1
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, Catania, Italy,
Dipartimento di Fisica e Astronomia, Università di Catania, Catania, Italy. 3Institut de
Physique Nucléaire, Université Paris-Sud-11-CNRS/IN2P3, France. 4Istituto Nazionale
di FisicaNucleare, Sezione di Pisa, Pisa, Italy. 5 Dipartimento di Fisica e Astronomia,
Università di Padova, Padova, Italy. 6Istituto Nazionale di FisicaNucleare, Sezione di
Padova, Padova, Italy. 7Istituto Nazionale di Fisica Nucleare, Sezione di Catania, I95125 Catania, Italy. 8Instituto de Fìsica da Universidade Federal Fluminense, Niteroì,
RJ, Brazil. 9Centre de Sciences Nucléaire set de Sciences de la Matières - CSNSM,
Université Paris-Sud-11-CNRS/IN2P3, France.
2
Giant resonances are collective excitation modes of many-body systems of fermions
governed by a mean field, such as the atomic nuclei. The microscopic origin of such
modes is the coherence among elementary particle-hole excitations, where a particle is
promoted from an occupied state below the Fermi level (hole) to an empty one above
the Fermi level (particle).
The same coherence is also predicted for the particle–particle and the hole–hole
excitations, because of the basic quantum symmetry between particles and holes. In
nuclear physics, the giant modes have been widely reported for the particle–hole sector
but, despite several attempts, there is no precedent in the particle–particle and hole–hole
ones, thus making questionable the aforementioned symmetry assumption. The Giant
Pairing Vibration (GPV) is the leading particle–particle giant mode.
Recently we have provided the first experimental signature of the GPV in light nuclei
14
C and 15C excited by the two-neutron transfer reaction (18O,16O) at 84 MeV incident
energy using the MAGNEX large acceptance magnetic spectrometer. These results,
published in Nature Commun. [1], will be presented and discussed. New data on the
measured neutron decay of the observed resonances of 15C, included the GPV, will be
also shown.
[1]
F. Cappuzzello, et al., Nat. Commun. 6:6743 doi: 10.1038/ncomms7743 (2015).
IFUNAM's Nuclear Physics facilities: new data and extensions.
Efraín Rafael Chávez Lomelí.
Instituto de Física, Universidad Nacional Autónoma de México, A.P. 20-364, México
D. F. 01000, México.
In the last 2-3 years several important pieces of infrastructure have been put in operation
at IFUNAM, greatly enlarging the horizon of the scientific program in Nuclear Physics:
-LEMA “Laboratorio de Espectrometría de Masas con Aceleradores”.
-SUGAR: Supersonic Gas Jet Target.
-MONDE: Momentum Neutron Detector.
-The upgraded 5.5 MV CN-Van de Graaff Accelerator laboratory.
In this talk, the present status of these facilities is briefly reviewed and some of the first
data and results are shown.
Finally, an important instrumentation development expected to be on line in the short
term (2016) is presented: the new astrophysics beam line at LEMA.
Title (to be confirmed)
Osvaldo Civitarese.
Universidad Nacional La Plata, Argentina.
Update on the Neutron Electric Dipole Moment
Christopher Crawford
Deparment of Physics and Astronomy, University of Kentuky, Kentuky, USA.
The electric dipole moment (EDM) of fundamental particles is a sensitive observable to
new physics due to its negligible background in the standard model. It requires CP
violation, which is one of the indredients needed to explain the baryon asymmetry of the
universe. The neutron is particularly suited for such experiments. Its EDM has been
constrained to less than $3\times10^{-26} e$ cm at the ILL [1]. Several groups
worldwide are preparing the next generation of experiments to increase the sensitivity
by one or two orders of magnitude. I will report on progress of experiments at the SNS
and PSI, with emphasis on the design uniform magnetic fields required for this level of
precision.
[1] J.M. Pendelbury, Phys. Rev. D 92, 092003.
Breakup/knockout of exotic nuclei from collision with a proton target:
developments and perspectives.
Raquel Crespo.
Universidade Técnica de Lisboa, Lisbon, Portugal.
Breakup/knockout reactions have been widely used by worldwide facilities to explore
nuclear structure for nuclei at/away the stability line. The reaction theory plays a key
role in the interpretation of the experimental data and one needs to identify and
incorporate all relevant dynamical effects to extract reliable information from
experimental results. Recent reaction theory developments for the study the
breakup/knockout of exotic nuclei will be shown. Particular attention will be devoted to
core excitation dynamical effects (1,2) in the reaction mechanism. The bridging and
benchmark of available reaction frameworks is a timely issue (3) and will be presented.
A systematic for nucleon knockout from nuclei at/away the stability line relevant for the
interpretation of current and future experiments (4) and future novel insights will be
discussed.
(1) R. Crespo, A. Deltuva, A.M. Moro, Phys. Rev C 83, 044622 (2011).
(2) A. Deltuva, Phys Rev C 88, 011601(R)(2013).
(3) R. Crespo, A. Delltuva, E. Cravo, Phys. Rev C90, 044606 (2014).
(4) E. Cravo, R. Crespo, A. Deltuva, Distortion effects on the nucleon knockout
from exotic nuclei with the collision with a proton target at Quasi-free
scattering, submitted for publication.
Amplitude Analysis of KN Scattering.
Cesar Fernández Ramirez.
Jefferson Lab, USA and Instituto de Ciencias Nucleares, Universidad Nacional
Autónoma de México, A.P. 70-543, 04510 México D.F., Mexico
I present a unitary multichannel model for 𝐾 𝑁 scattering in the resonance region that
fulfills unitarity, it has the correct analytical properties for the amplitudes once they are
extended to the complex-s plane and the partial waves have the right threshold behavior.
To determine the parameters of the model we have fitted single-energy partial waves up
to J=7/2 and up to 2.15 GeV of energy in the center of mass reference frame obtaining
the poles of the Lambda and Sigma resonances, which are compared to previous
analysis.
We provide the most comprehensive picture of the S=-1 hyperon spectrum to the date
and some important differences are found between the available analyses deeming the
gathering of further experimental information on KN scattering mandatory in order to
make progress in the assessment of the hyperon spectrum. I will also comment on the
Lambda (1405) and its nature as well as on the impact of KN amplitudes in pentaquark
searches at LHCb.
The Triangular D3h Symmetry of 12C
Moshe Gai.
LNS at Avery Point, University of Connecticut, USA.
Recent measurements of the structure of 12C [1] using an optical readout TPC (O-TPC)
[2] and gamma beams allowed the first study of the rotation vibration spectrum of 12C
which appears strikingly similar to the spectrum predicted by a new algebraic cluster
model [3] employing a geometrical triangular shape with (D3h) symmetry with
predicted recurring rotational bands including the states: 0+, 2+, 3-, (degenerate) 4+ and
4-, 5- etc [4,5]. Such structures and symmetries are common in molecular physics, but
have been observed in nuclear physics for the first time. This model also allow us to
elucidate the structure of the Hoyle state and as such it is in conflict with ab-initio
effective field theory calculations on the lattice [6] that predict a
different structure of the Hoyle state. The calculations on the lattice on the other hand
use the Hoyle state to conclude the masses of light quarks and the strength of the
electromagnetic interaction (within the anthropic view of the universe). Extension of
this study to the newly constructed ELI-NP gamma ray facility in Bucharest with a
Warsaw-UConn-ELI electronic readout TPC (eTPC) will be discussed.
[1] W.R. Zimmerman et al.; Phys. Rev. Let. 110, 152502 (2013).
[2] M. Gai et al.; JINST 5, 12004 (2010).
[3] R. Bijker and F. Iachello; Phys. Rev. C61, 067305 (2000),
ibid Ann. Phys. 298, 334 (2002).
[4] D.J. Marin-Lambarri et al.; Phys. Rev. Lett. 113, 012502 (2014).
[5] Kevin Dusling, Physics, Synopsis:
http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.113.012502,
Hamish Johnston, Physicsworld.com;
http://physicsworld.com/cws/article/news/2014/jul/08/carbon-nucleus-seen
spinning-in-triangular-state
[6] E. Epelbaum et al.; Phys. Rev. Lett., 110, 112502 (2013).
Overview of Experimental Physics Results at Oak Ridge National
Laboratory: From neutrinos to cluster.
Alfredo Galindo-Uribarri.
Oak Ridge National Laboratory. USA.
In the first part of my talk I will describe some of the common challenges and
techniques between the fields of Accelerator Mass Spectrometry (AMS) and
Radioactive Ion Beam (RIB) science. I will present our recent results on the search for
doubly charged negative atoms and on our study on the production of large clusters of
anions. I will then describe our AMS efforts to broaden the range of radionuclides that
can be detected at ultra-low levels of interest to the search for neutrinoless double-beta
decay and other underground experiments.
Finally, I will describe some recent activities on neutrino physics that are providing
important research opportunities to students from around the world. The Spallation
Neutron Source and the High Flux Reactor at Oak Ridge National Laboratory are two
very powerful neutrino sources that open new physics opportunities.
Latest news from the High Altitude Water Cherenkov Observatory
Adiv González Muñoz.
Instituto de Física, Universidad Nacional Autónoma de México, A.P. 20-364, México
D. F. 01000, México
The High Altitude Water Cherenkov Observatory (HAWC) is an air shower detector
designed for the study of very-high-energy gamma rays (~100 GeV to ~100 TeV). It is
located in the Pico de Orizaba National Park, Mexico, at an elevation of 4100 m.
HAWC unique capabilities, with a field of view of ~2 sr and a high duty cycle >95%,
allow it to survey 2/3 of the sky every day. These features makes HAWC an excellent
instrument for searching new TeV sources and for the detection of transient events, like
gamma-ray bursts. Moreover, HAWC provide almost continuous monitoring of already
known sources with variable gamma-ray fluxes in the most of northern and part of the
southern sky. These observations will bring new information about the acceleration
processes that take place in astrophysical environments. HAWC started operations since
August 2013 with 111 tanks and in April of 2015 the 300 tanks array was completed. In
this talk some of the latest scientific results of the observatory will be presented.
Different aspects on the effect of 6Li resonances on elastic scattering.
A. Gómez-Camacho1 and A.Díaz-Torres2
1
Instituto Nacional de Investigaciones Nucleares, Apartado postal 18-1027, C.P.
11801, México, D.F., Mexico. 2European Centre for Theoretical Studies in Nuclear
Physics and Related Areas, Strada delle Tabarelle, 286, I-38123 Villazzano Trento,
Italy
CDCC calculations of elastic scattering angular distributions for reactions of
the weakly bound projectile 6Li, with 144Sm at energies around the Coulomb barrier
are performed.In the calculations, ground, resonant and non-resonant continuum states
of 6Li→α+d are included.
In the continuum space, resonance statesl=2, Jπ=3+, 2+, 1+, are discretized so as to
reproduce the corresponding experimental resonance energies and widths.
In the convergent calculations, energy and target mass dependent systematic potentials
α-target and deuteron-target are used. The calculations with the complete discretized
energy space are in good agreement with the data.
To investigate the effect the resonance continuum states of 6Li on elastic scattering, two
types of calculations are carried out. That is, (a) by omitting from the continuum energy
spectrum all states where the resonances are constructed in the discretization process,
and (b) by considering only the resonance discretized space. The results show some
effect when compared to the full calculation with all continuum states.
It is also observed that the strength of this effect varies with the dispersion angle. At low
energies, the effect is stronger at high dispersion angles, however, it shifts to lower
angles as the energy increases. On the other hand, the calculations where only the
resonance discretized space is considered are very similar to the full calculation. So,
resonance states produce stronger repulsive couplings than non-resonance ones.
The different effects of non-resonant and resonant discretized states of 6Li on elastic
scattering, are interpreted in terms of the polarization potentials that emerge in the
couplings and in terms of the distance of closest approach between the nuclei.
The concept of forbiddenness in cluster physics
Peter O. Hess1 and H. Yépez Martínez2
1
Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A.P.
70-543, 04510 México D.F., Mexico, 2Universidad Autónoma de la Ciudad de
México, Mexico.
In 1984 Yu. Smirnov and T. M. Tchuvil’sky proposed the concept of forbiddeness in
cluster physics. They showed that it plays an important role in structural considerations
in heavy ion collisions. Many observable results could be explained by it. However,
because some mismatches appears with the above definition of forbiddenness the
concept of forbiddenness has to be revisited. We show where the difficulty arises and
provide a new expression for the forbiddenness. The new method is easier than the
method provided by Smirnov et al.. We also present some applications to the 236U and
252
Cf nuclei.
Color reconnection: a fundamental ingredient of the hadronisation in
pp collisions.
Sergio Arturo Iga.
Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A.P. 70543, 04510 México D.F., Mexico.
At the LHC very interesting similarities among different colliding systems (pp, p-Pb
and Pb-Pb) where observed in the multiplicity evolution of the transverse momentum
spectra. This has prompted a number of analyses that have explained the results in terms
of collective hydro flow. The explanation in terms of hydrodynamics has recognized
problems with the smallness of the interaction volume in the systems created in pp and
p-Pb collisions. On the other hand, some event generators based on QCD produce a
reasonable qualitative, and sometimes quantitative, agreement with the data. Those
results can be achieved introducing in the hadronisation model the so-called color
reconnection (CR) which produces flow-like patterns via boosted strings. In this work
we present the behavior of the various CR schemes compared to those without the CR
case for different center-of-mass energies at the LHC (0.9, 7 and 13 TeV).
Structure of light nuclei with low energy nuclear reactions.
Ivano Lombardo and D. Dell’Aquila
Università degli Studi di Napoli Federico II and INFN and Sezione di Napoli
Via Cintia, Compl. Univ. M.S.Angelo, I-80126, Napoli, Italy.
The study of the Structure of light nuclei is an important topic in Nuclear Physics. In
fact, light nuclear systems can manifest interesting phenomena as the appearance of clustering [1]. Unfortunately, many ambiguities are still persisting in the level schemes
of these nuclei, and this prevents a deep understanding of their structure [2]. To refine
the spectroscopy of several light nuclei we started a campaign of low energy nuclear
reaction experiments, mainly aimed at the study of light self-conjugated nuclei (in
particular 20Ne and 12C) and carbon isotopes (in particular 11C and 13C). The
experiments have been performed at the TTT-3 tandem accelerator in Naples and
AN2000 and CN accelerators in Legnaro. The analysis of reactions 19F(p,α0) [3,4],
10
B(p,α0) [5], 14N(d, α) and scattering experiment 9Be(α, α) [6] allowed to solve some
ambiguities on the Jπ assignment of levels of 20Ne and 11,12,13C respectively, and pointed
out the possible presence of α-cluster excited states in these nuclei. Results of these
experiments will be discussed in the talk, together with some perspectives on future
investigations.
References
[1] W. von Oertzen, M. Freer and Y. Kanada-En’Yo, Phys. Rep. 432 (2006) 43-113
[2] http://www.tunl.duke.edu/nucldata/
[3] I. Lombardo et al, J. Phys. G 40 (2013) 125102
[4] I. Lombardo et al, Phys. Lett. B 748 (2015) 178-182
[5] I. Lombardo et al, submitted to J. Phys. G
[6] I. Lombardo et al, Nucl. Instrum. Meth. Phys. Res. B 302 (2013) 19-22
Antinuclei and (anti-)hypernuclei studies at the LHC
Arturo Menchaca Rocha.
Instituto de Física, Universidad Nacional Autónoma de México, A.P. 20-364, México
D. F. 01000, México.
At LHC energies, the production of antibarions is sufficient to allow the synthesis of
A<=4 antinuclei and (anti-)hyper nuclei, some of them observed for the first time. This
production of exotic nuclei opens new possibilities for nuclear studies. For example, the
abundance of A<=3 nuclei & antinuclei allowed to test, with the highest precession yet,
CPT conservation at the nuclear level. Note that these nuclear species have also been
observed, although with less abundance, in p-p collisions. On the other hand, the yield
of Lambda-0´s in Pb-Pb also lead to the observation of hyper tritium and hyper 3He, as
well as their charge-conjugates. The production of neutral A>= 4 hyper nuclei has also
been predicted, for which ALICE would be best suited to observe.
Phase transitions for rotational states within an algebraic cluster
model
Enrique López Moreno1, G. E. Morales Hernández2, P. O. Hess2 and H. Yépez
Martínez3
1
Departamento de Física, Facultad de Ciencias, Universidad Nacional Autónoma de
México, México D.F., Mexico. 2Instituto de Ciencias Nucleares, Universidad
Nacional Autónoma de México, A.P. 70-543, 04510 México D.F., Mexico.
and 3Universidad Autónoma de la Ciudad de México.
The Semimicroscopic Algebraic Cluster Model [1, 2] is a successful cluster model for
nuclei. It takes into account the Pauli exclusion principle, a necessary one for any
cluster model. It was successfully applied to nuclei in the sd shell, where one of the last
applications is published in [3]. Cluster systems of astrophysical interest were
considered and also spectroscopic factors [4] calculated. A detailed study of quantum
phase transitions of the ground state where published in [5, 6]. However, this study was
done in a pedestrian way, not using the latest technology available, which is the
catastrophe theory [7]. Exited, rotational states were considered in [8], but also here the
treatment was simple.
The objective of this contribution is to use the catastrophe theory to nuclear cluster
system, in order to study in a very effective and detailed manner way the structure of
phase transitions in nuclear cluster systems, in the ground state and for excited states.
The catastrophe theory was applied with great success, also in nuclear systems [9, 10].
Of special interest, because of its relation to the case presented here, are algebraic
models treated in [11], [12].
[1] J. Cseh, Phys. Lett. B 281 (1992), 173.
[2] J. Cseh and G. Lévai, Ann. Phys. (N.Y.) 230 (1994), 165.
[3] H. Yépez-Martínez, P. R. Fraser, P. O. Hess and G. Lévai, Phys. Rev. C 86 (2012), 034309.
[4] P. O. Hess, A. Algora, J. Cseh and J. P. Draayer, Phys. Rev. C 70 (2004), 051303(R).
[5] H. Yépez-Martínez, P. R. Fraser, P. O. Hess and G. Lévai, Phys. Rev. C 85 (2012), 014316.
[6] P. R. Fraser, H. Yépez-Martínez, P. O. Hess and G. Lévai, Phys. Rev. C 85 (2012), 014317.
[7] R. Gilmore, Catastrophe Theory for Scientists and Engineers, (Wiley,New York, 1981).
[8] G E Morales-Hernández, H Yépez-Martínez and P O Hess, J. Phys.: Conf. Series 387
(2012), 012019.
[9] Enrique López-Moreno, Deformaciones nucleares y estabilidad de modelos colectivos.
Ph.D. Thesis, Universidad Nacional Autónoma de México (1998)
[10] Enrique López-Moreno, and Octavio Castaños, Shapes and stability within the interacting
boson model: Dynamical symmetries, Phys. Rev. C, 54 (1996) 2374.
[11] E. López-Moreno, M. Grether and V. Velázquez, J. Phys. A bf 44 (2011), 475301.
[12] E. López-Moreno, M. Grether, Quantum Studies: Mathematics and foundations bf 1
(2014), 203-211.
On the robustness of the r-process in neutron-starmergers against changes of
nuclear masses
Joel de Jesús Mendoza-Temis
Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A.P. 70543, 04510 México D.F., Mexico and Centro de Ciencias de la Complejidad,
Universidad Nacional Autónoma de México, D.F., Mexico.
We have performed r-process calculations for matter ejected dynamically in neutron star
mergers based on a complete set of trajectories from a three-dimensional relativistic
smoothed particle hydrodynamic simulation with a total ejected mass of ~ 1.7×10-3 M⦿.
Our calculations consider an extended nuclear network, including spontaneous, - and
neutron-induced fission and adopting fission yield distributions from the ABLA code.
In particular we have studied the sensitivity of the r-process abundances to nuclear
masses by using diferent mass models for the calculation of neutron capture cross
sections via the statistical model. Most of the trajectories, corresponding to 90% of the
ejected mass, follow a relatively slow expansion allowing for all neutrons to be
captured. The resulting abundances are very similar to each other and reproduce the
general features of the observed r-process abundance (the second and third peaks, the
rare-earth peak and the lead peak) for all mass models as they are mainly determined by
the fission yields. We find distinct differences in the predictions of the mass models at
and just above the third peak, which can be traced back to different predictions of
neutron separation energies for r-process nuclei around neutron number N = 130.
Addionally we find that at timescales of weeks relevant for kilonova light curve
calculations, the abundance of actinides is larger than the one of lanthanides. This
means that actinides can be even more important than lanthanides to determine the
photon opacities under kilonova conditions.
Structures of neutron drip-line nuclei
Takashi Nakamura.
Tokyo Institute of Technology, Tokyo, Japan.
Characteristic features of weakly bound and barely unbound nucleinear the neutron drip
line are discussed. Weakly bound nuclei often exhibit neutron halo structure, while
barely unbound nuclei may show novel few-body resonances. As such, these nuclei
lying at the extreme of the nuclear chart have recently attracted much attention. I will
show recent experimental studies performed using breakup reactions at the new
generation RI-beam facility RIBF (RI-beam Factory) at RIKEN.
In particular, I will show results on unbound oxygen isotopes, 25O and 26O, which has
been one of recent focuses, as keys to understand three nucleon forces, shell evolution,
and continuum effects near the nuclear bound limit. I will also discuss neutron halo
nuclei, such as 31Ne and 22C, and other cases of unbound nuclei to clarify the
characteristic features of weakly bound and unbound nuclei.
Electromagnetic properties of the I=11/2- isomers in the Cd isotopes:
What can we learn from them?
Stuart Pittel.
University of Delaware, USA.
The electromagnetic features of the 11/2- isomers in 111-127Cd are reproduced by
numerically optimized shell-model wave functions. A sudden phase change of the wave
function at N = 70 is identified and further confirmed by the evolution of BE2(7/2- →
11/2-) values. This phase change gives rise to different linear relations between the Q
and mu values with N<70 and N>70, as needed to reproduce the experimental data. The
particle-hole transformation properties for h11/2 neutrons in a well-isolated subshell
involving degenerate s1/2, d3/2, d5/2, and h11/2 orbits is suggested as a possible
explanation for this phase change.
Heavy-ion results at the LHC: new discoveries and puzzles.
Antonio Ortiz.
Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A.P. 70543, 04510 México D.F., Mexico.
The aim of the heavy-ion program is to study the physics of strongly interacting matter
at extreme energy densities, where the formation of the quark-gluon plasma (QGP) is
expected.
A review of the heavy-ion results at the LHC will be presented. It will mainly focus on
the recent discovery of QGP-like signatures in the small systems created in pp and pA
collisions. The implications in our understanding of QGP and the theoretical
interpretations will be discussed.
ATLAS at the LHC - Recent results from Run 2
Oliver Stelzer-Chilton
TRIUMF, Vancouver, Canada.
ATLAS is one of the two multi-purpose experiments at the Large Hadron Collider in
Geneva Switzerland. The discovery of the Higgs boson in Run 1 marks a milestone in
Particle Physics that lead to the Nobel Prize in Physics awarded to Higgs and Englert in
2013. In this talk I will present the status of Higgs boson and Standard Model
measurements and results on searches for physics beyond the Standard Model.
Highlights will include recent results from Run 2 at 13 TeV center of mass energy.
The Joint Physics Analysis Center.
Adam Szczepaniak.
Indiana University and JLab. USA.
I will give an overview of the activities of the Joint Physics Analysis Center.
Title (to be confirmed)
Carlos Vargas.
Universidad Veracruzana, Mexico.
Double beta decay with the SNO+ detector.
Eric Vázquez Jáuregui.
Instituto de Física, Universidad Nacional Autónoma de México, A.P. 20-364, México
D. F. 01000, México.
SNO+ is the successor of the SNO experiment, where the heavy water has been
replaced by 780 tons of liquid scintillator (linear alkyl benzene, LAB). SNO+ is located
in the SNOLAB underground facility, near Sudbury Ontario Canada, 2 km below the
surface to mitigate backgrounds produced by cosmic rays, and in a clean lab
environment (class 2000) to reduce external backgrounds. The SNO+ experiment will
use the infrastructure inherited from SNO, including the 12 m diameter acrylic vessel
surrounded by almost 10000 PMTs, with some diverse modifications such as a holddown rope net system and upgrades to the data acquisition.
The physics programme will be initially focused in the search for the neutrino-less
double beta decay, by adding tellurium to the scintillator (0.3% by weight, 160 kg Te130). The experiment will reach a sensitivity of 9×1025 yrs. (90% C.L.) after 5 years of
data taking. The limit will be reached due to the intense purification programme for the
scintillator and tellurium. The physics goals of the experiment also include low energy
solar neutrinos, geo and reactor neutrinos, supernova neutrinos if one occurs, as well as
nucleon decay and dark matter search through axions.
In this talk, I will present the current status of the SNO+ experiment and discuss its
physics programme focusing in the double beta decay phase.
Quantum complexity in Ca48 and Ti48
Víctor Velázquez
Facultad de Ciencias, Universidad Nacional Autónoma de México, México D.F.,
Mexico.
In a previouswork [1] wehavereportedthemerginginterferencepattern in the nuclear
energydistribution as a function of the statistical mixing of the shell model quantum
states driven by the two body quadrupole-quadrupole interaction in Ca48. In
thiscontributionweextendthisanalysistonucleusthatincludesprotons in thevalenceorbitals.
Westudy quantum chaos comparingthecomplexitybetweenboth Ca48 and Ti48.
[1] "Quantum Interference vs. quantum chaos in the nuclear shellmodel". G. Fernández
et al., Journal of Physics: Conferences Series 578 (2015) 012014, XXXVII
Symposiumon Nuclear Physics.
Title (to be confirmed)
Giuseppe Verde.
IPN-Orsay, France.
Analysis of a motivated QCD Hamiltonian at low energy regime.
Tochtli Yepez.
UNLP, La Plata, Argentina.
We present an extensive analysis of an effective Hamiltonian motivatedfrom the QCD
Hamiltonian in Coulomb gauge, at low energy. Using a confining interaction between
quarks we analyze the low energy spectrum as a function of a few parameters by
implementation of many body methods like Tamm-Dancoff. We will also discuss some
special features of the spectrum as well as possible procedures to look for a better
understanding of the interaction of quarks and their dynamics, essential for future
incorporation of dynamical gluons and their interactions.
Poster Session.
A many-body approach to non-perturbative QCD.
David Arturo Amor Quiroz, Danna Oassis Pérez López, Peter Otto Hess Bechstedt
Instituto de Ciencias Nucleares UNAM, AP 70-543, 04510 México DF, Mexico.
We present the current state of development of a many-body approach to non
perturbative QCD. We propose a QCD-oriented Hamiltonian where only the quark
sector is considered. The quark-quark interaction is approximated by a static potential
consisting in a combination of a part proportional to 1/r and a confining part linear in r.
We explore the use of different basis to expand the fields and then apply the TammDankoff approach to obtain first results. We also report on the next step, the application
of the RPA method and the inclusion of the flavor symmetry breaking.
Coupled channel calculations for the 10C+58Ni system.
Araceli García Flores1,2, E. F. Aguilera1, T.L. Belyaeva2.
1
Departamento de Aceleradores, Instituto Nacional de Investigaciones Nucleares,
Apartado postal 18-1027, C.P. 11801, México, D.F., Mexico.
2
Facultad de Ciencias, Universidad Autónoma del Estado de México, C.P. 50000,
Toluca, México.
In this work, we present coupled channel (CC) calculations of elastic scattering cross
sections for the 10C+58Ni system. Elastic and inelastic reactions give information about
the behavior of nuclei. In the first step we made the calculations considering both
nuclei in the ground state. The inelastic couplings were treated within the vibrational
model for 58Ni (including transitions from the 0+ gs to the 2+ and 3- vibrational states)
and the rotational model was used for 10C, including transitions from the ground state to
the first-excited 2+ state. Results are shown for the elastic scattering angular
distributions at 27, 28, 29 and 30 MeV, with and without the inelastic coupling, so the
effect of the couplings can be assessed. These CC calculations were performed using the
code FRESCO.
Quantum chaos signatures in 48Ca.
Diego Alberto Lara Bustillos.
Facultad de Ciencias, UNAM, Mexico.
In this poster we present a study of the three methods for characterization of quantum
chaos: Power spectrum; near neighbour energy levels analysis; and visivility of state
interference. All results are in agree. We can outline two mean fluctuations noises:
1 1
,
𝑓 2 𝑓1
and transitions between themselves.
Z' Resonance and Associated ZH Production with the addition of the
B-L model at Future Higgs Boson Factory: ILC and CLIC
Francisco Ramírez Sánchez.
Unidad Académica de Física. Universidad Autónoma de Zacatecas. Zacatecas,
Mexico.
We study the prospects of the B-L (Baryon minus Lepton) model with an additional Z'
to be a Higgs Boson Factory at high energy and high luminosity linear electron positron
colliders, such as the ILC and CLIC, through the Higgs-Strahlung process e+ e−→ (Z,Z')
→ ZH, including both, the resonant and the non-resonant effects. We evaluate the total
cross section of ZH and calculate the total number of events for integrated luminosities
of 500-3000 fb-1 and center of mass energies between 500 and 3000 GeV. We found
that the total number of expected ZH events can reach 10-6, which is a very optimistic
scenario and it would be possible to perform precision measurements of both Z' and
Higgs Bosons in future high energy e+ e− colliders experiments.
MONDE: MOmentum Neutron DEtector.
Pedro Humberto Santa Rita Alcibia.
Instituto de Física, Universidad Nacional Autónoma de México, A.P. 20-364, México
D. F. 01000, México.
MONDE is a large area neutron momentum detector, consisting of a 70x160x5 cm3
plastic scintillator slab surrounded by 16 photomultiplier tubes, standard NIM signal
processing electronics and a CAMAC data acquisition system.
Data from incident gamma rays (60Co) and neutrons (AmBe) were used to characterize
the position resolution of MONDE.
First results with an "external" trigger are presented too.
Year of birth determination using radiocarbon dating of tooth
collagen.
Eduardo Solis Meza.
Instituto de Física, UNAM, Mexico.
As a result of nuclear bomb testing during the cold war, the amount of radiocarbon
presents in tooth collagen is a remarkably accurate indicator of when a person is born.
Collagen isolated from human teeth is processed to form graphite. Carbon-14 levels are
measured using accelerator mass spectrometry. Since there is no turnover of collagen
after it is formed, 14C levels in the collagen represent 14C levels in the atmosphere at the
time of its formation. In this work we describe the strategy used to determine the date of
birth of an individual based on radiocarbon levels in tooth collagen. Year of birth
information can significantly assist police investigators when the identity of a deceased
individual is unknown.