Nuclear Theory·nucl-th

Tuesday·July 9, 2019

14 papers—8 primary·6 cross-listed

01
[Submitted on 5 Jul 2019]
Shell Model Calculations for Proton-rich Zn Isotopes via New Generated Effective Interaction by Artificial Neural Networks
Serkan Akkoyun
In this study, the artificial neural network method has been employed for the generation of the new two-body matrix elements which is used for pfg shell nuclei. For this purpose, jj44b interaction Hamiltonian has been considered as a source. After the generation of the new Hamiltonian, both, original and new generated, are tested on proton-rich Zn isotopes. According to the results, the calculated values are close to the each other. As well the results from new interaction (jj44b_nn) are closer to the available experimental values in some cases.
Comments:
8 pages, 1 table, 2 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1907.03015 [pdf]
0 citations
02
[Submitted on 5 Jul 2019]
The role of the local conservation laws in fluctuations of conserved charges
Peter Braun-Munzinger🇩🇪 · Anar Rustamov🇩🇪 · Johanna Stachel🇩🇪
In this report we present the first quantitative determination of the correlations between baryons and anti-baryons induced by local baryon number conservation. This is important in view of the many experimental studies aiming at probing the phase structure of strongly interacting matter. We confront our results with the recent measurements of net-proton fluctuations reported by the CERN ALICE experiment. The role of local baryon number conservation is found to be small on the level of second cumulants.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1907.03032 [pdf]
36 citations
03
[Submitted on 6 Jul 2019]
Projection of Good Quantum Numbers for Reaction Fragments
Aurel Bulgac
In reactions the wave packets of the emerging products typically are not eigenstates of particle number operators or any other conserved quantities and their properties are entangled. I describe a particle projection technique in parts of space, which eschews the need to evaluate Pfaffians in the case of overlap of generalized Slater determinants or Hartree-Fock-Bogoliubov type of vacua. The extension of these formulas for calculating either angular momentum or particle projected energy distributions of the reaction fragments are presented as well. The generalization to simultaneous particle and angular momentum projection of various reaction fragment observables is straightforward.
Comments:
Published version, 7 pages, 2 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1907.03056 [pdf]
PRC(2019)·22 citations
04
[Submitted on 6 Jul 2019]
Hot neutron stars with microscopic equations of state
Jia-Jing Lu · Zeng-Hua Li · G. F. Burgio · H.-J Schulze
We study the properties of hot beta-stable nuclear matter using equations of state derived within the Brueckner-Hartree-Fock approach at finite temperature including consistent three-body forces. Simple and accurate parametrizations of the finite-temperature equations of state are provided. The properties of hot neutron stars are then investigated within this framework, in particular the temperature dependence of the maximum mass. We find very small temperature effects and analyze the interplay of the different contributions.
Comments:
8 pages, 7 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)
arXiv:
1907.03120 [pdf]
PRC(2019)·50 citations
05
[Submitted on 7 Jul 2019]
Constraints from the GW170817 merger event on the nuclear matter equation of state
G. F. Burgio🇮🇹 · A. Figura🇮🇹 · H.-J. Schulze🇮🇹 · J.-B. Wei (Dipartimento di Fisica e Astronomia, Universita' di Catania, and INFN Sezione di Catania)🇮🇹
The detection of the GW170817 neutron star merger event has incited an intense research activity towards the understanding of the nuclear matter equation of state. In this paper we compare in particular the pressure-density relation obtained from heavy-ion collisions with the analysis of the NS merger event. Moreover, we present recent calculations of neutron star's moment of inertia and tidal deformability using various microscopic equations of state for nuclear and hybrid star configurations, and confirm several universal relations. We also discuss the recent constraints for the NS radii determined by GW170817, and find compatible radii between 12 and 13 kilometers, thus identifying the suitable equations of state.
Comments:
Talk given by G. F. Burgio at XIII Quark Confinement and the Hadron Spectrum - Confinement2018 - 31 July - 6 August 2018, Maynooth University, Ireland
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)
arXiv:
1907.03283 [pdf]
PoS(2018)·3 citations
06
[Submitted on 7 Jul 2019]
System size scan of D meson $R_{AA}$ and $v_{n}$ using PbPb, XeXe, ArAr, and OO collisions at LHC
Roland Katz🇫🇷 · Caio A. G. Prado🇨🇳 · Jacquelyn Noronha-Hostler🇺🇸 · Alexandre A. P. Suaide🇧🇷
Experimental measurements indicate no suppression (e.g. $R_{pPb} \sim 1$ ) but a surprisingly large D meson $v_{2}$ was measured in pPb collisions. In order to understand these results we use Trento+v-USPhydro+DAB-MOD to make predictions and propose a system size scan at the LHC involving $^{208}$ PbPb, $^{129}$ XeXe, $^{40}$ ArAr, and $^{16}$ OO collisions. We find that the nuclear modification factor approaches unity as the system size is decreased, but nonetheless, in the 0-10% most central collisions $v_{2} {2}$ is roughly equivalent regardless of system size. These results arise from a rather non-trivial interplay between the shrinking path length and the enhancement of eccentricities in small systems at high multiplicity. Finally, we also find a surprising sensitivity of D mesons $v_{2} {2}$ in 0-10% at $p_{T} = 2 - 10$ GeV to the slight deformation of $^{129}$ Xe recently found at LHC.
Comments:
11 pages, 12 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1907.03308 [pdf]
PRC(2020)·47 citations
07
[Submitted on 8 Jul 2019]
Towards high-order calculations of three-nucleon scattering in chiral effective field theory
E. Epelbaum · J. Golak · K. Hebeler · H. Kamada · H. Krebs · U.-G. Meißner · A. Nogga · P. Reinert · R. Skibiński · K. Topolnicki · Y. Volkotrub · H. Witała
We discuss the current status of chiral effective field theory in the three-nucleon sector and present selected results for nucleon-deuteron scattering observables based on semilocal momentum-space-regularized chiral two-nucleon potentials together with consistently regularized three-nucleon forces up to third chiral order. Using a Bayesian model for estimating truncation errors, the obtained results are found to provide a good description of the experimental data. We confirm our earlier findings that a high-precision description of nucleon-deuteron scattering data below pion production threshold will require the theory to be pushed to fifth chiral order. This conclusion is substantiated by an exploratory study of selected short-range contributions to the three-nucleon force at that order, which, as expected, are found to have significant effects on polarization observables at intermediate and high energies. We also outline the challenges that will need to be addressed in order to push the chiral expansion of three-nucleon scattering observables to higher orders.
Comments:
14 pages, 12 figures, 1 table; contribution to the EPJA topical issue on "The tower of effective (field) theories and the emergence of nuclear phenomena"
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1907.03608 [pdf]
EPJA(2020)·96 citations
08
[Submitted on 8 Jul 2019]
Scale and Scheme Independence and Position-Momentum Equivalence of Nuclear Short-Range Correlations
R. Cruz-Torres · D. Lonardoni · R. Weiss · N. Barnea · D. W. Higinbotham · E. Piasetzky · A. Schmidt · L. B. Weinstein · R. B. Wiringa · O. Hen
Ab-initio Quantum Monte Carlo (QMC) calculations of nuclei from deuterium to 40Ca, obtained using four different phenomenological and local chiral nuclear potentials, are analyzed using the Generalized Contact Formalism (GCF). We extract spin- and isospin-dependent "nuclear contact terms" for each interaction in both coordinate and momentum space. The extracted contact terms, that count the number of short-range correlated (SRC) pairs with different quantum numbers, are dependent on the nuclear interaction model used in the QMC calculation. However, the ratios of contact terms for a nucleus A to deuterium (for spin-1 pn pairs) or to 4He (for all NN pairs) are independent of the nuclear interaction model and are the same for both short-distance and high-momentum pairs. This implies that the relative abundance of short-range pairs in the nucleus is a long-range (mean-field) quantity that is insensitive to the short-distance nature of the nuclear force. Measurements of exclusive (e,e'NN) pair breakup processes are instead more sensitive to short-range dynamics
Comments:
Published in Nature Physics. 8 pages, 6 figures 1 table
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1907.03658 [pdf]
Nat.Phys.(2021)·104 citations

Affiliations

first authorsco-authorsvia INSPIRE