Nuclear Theory·nucl-th

Friday·August 9, 2019

13 papers—6 primary·7 cross-listed

01
[Submitted on 7 Aug 2019]
Chiral crossover characterized by Mott transition at finite temperature
Shijun Mao🇨🇳
We discuss the proper definition for the chiral crossover at finite temperature, based on the Goldstone's theorem. Different from the usually used maximum change of chiral condensate, we propose to define the crossover temperature by the Mott transition of pseudo-Goldstone bosons, which, by definition, guarantees the Goldstone's theorem. We analytically and numerically demonstrate this property in frame of a Pauli-Villars regularized NJL model. In external magnetic field, we find that the Mott transition temperature shows an inverse magnetic catalysis effect.
Comments:
6 pages, 2 figs, 2 tables
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Lattice (hep-lat)
arXiv:
1908.02851 [pdf]
CPC(2021)·18 citations
02
[Submitted on 8 Aug 2019]
Neutron skins of heavy nuclei and tidal deformability of neutron star
Bharat Kumar
In this paper, I have discussed the numerical predictions for the neutron-skin thickness (NST) of various finite nuclei starting from $^{40}$ Ca to $^{238}$ U using recently developed effective relativistic mean-field models G3 and IOPB-I \cite{G3, IOPB}. The calculated results are compared with the PREX-II data, and the experiment has been done with antiprotons at CERN. Further, I have also calculated the dimensional tidal deformability of a canonical neutron star 1.4 $M_{⊙}$ and compared it with the recent observation of GW1701817.
Comments:
Accepted; The 15th International Symposium on Origin of Matter and Evolution of Galaxies (OMEG15) at Kyoto University, Japan
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1908.02909 [pdf]
JPS Conf.Proc.(2020)·1 citation
03
[Submitted on 8 Aug 2019]
Viscous coefficients and thermal conductivity of a $π K N$ gas mixture in the medium
Pallavi Kalikotay🇮🇳 · Nilanjan Chaudhuri🇮🇳 · Snigdha Ghosh🇮🇳 · Utsab Gangopadhyaya🇮🇳 · Sourav Sarkar🇮🇳
The temperature and density dependence of the relaxation times, thermal conductivity, shear viscosity and bulk viscosity for a hot and dense gas consisting of pions, kaons and nucleons have been evaluated in the kinetic theory approach. The in-medium cross-sections for $π π$ , $π K$ and $π N$ scatterings were obtained by using complete propagators for the exchanged $ρ$ , $σ$ , $K^{*}$ and $Δ$ excitations derived using thermal field theoretic techniques. Notable deviations can be observed in the temperature dependence of $η$ , $ζ$ and $λ$ when compared with corresponding calculations using vacuum cross-sections usually employed in the literature. The value of the specific shear viscosity $η / s$ is found to be in agreement with available estimates.
Comments:
Version published in European Physical Journal A
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1908.02933 [pdf]
EPJA(2020)·7 citations
04
[Submitted on 8 Aug 2019]
Kinetic freeze-out in central heavy-ion collisions between 7.7 and 2760 GeV per nucleon pair
Ivan Melo🇸🇰 · Boris Tomasik🇸🇰
We fit the single-particle $p_{t}$ spectra of identified pions, kaons, and (anti)protons from central collisions of gold or lead nuclei at energies between 7.7 and 2760~GeV per nucleon pair. Blast wave model with included resonance production and with an assumption of partial chemical equilibrium is used and the fits are performed with the help of a Gaussian emulator process. A kinetic freeze-out temperature is found about 100~MeV for the lowest collision energies and 80~MeV at the LHC. The average transverse expansion velocity grows with increasing $s_{N N}$ from 0.45 to 0.65. Due to partial chemical equilibrium, the influence of resonance decays on the shape of the $p_{t}$ spectra for $s_{N N}$ above 27~GeV is small.
Comments:
21 pages, 12 figures, updated version with improved explanations in the text, results not changed, some figures from the previous version were split, therefore the new version includes more figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1908.03023 [pdf]
J.Phys.G(2020)·23 citations
05
[Submitted on 8 Aug 2019]
A first step in the nuclear inverse Kohn-Sham problem: from densities to potentials
G. Accorto · P. Brandolini · F. Marino · A. Porro · A. Scalesi · G. Colò · X. Roca-Maza · E. Vigezzi
Nuclear Density Functional Theory (DFT) plays a prominent role in the understanding of nuclear structure, being the approach with the widest range of applications. Hohenberg and Kohn theorems warrant the existence of a nuclear Energy Density Functional (EDF), yet its form is unknown. Current efforts to build a nuclear EDF are hindered by the lack of a strategy for systematic improvement. In this context, alternative approaches should be pursued and, so far, an unexplored avenue is that related to the inverse DFT problem. DFT is based on the one-to-one correspondence between Kohn-Sham (KS) potentials and densities. The exact EDF produces the exact density, so that from the knowledge of experimental or {\it ab initio} densities one may deduce useful information through reverse engineering. The idea has already been proven to be useful in the case of electronic systems. The general problem should be dealt with in steps, and the objective of the present work is to focus on testing algorithms to extract the Kohn-Sham potential within the simplest ansatz from the knowledge of the experimental neutron and proton densities. We conclude that while robust algorithms exist, the experimental densities present some critical aspects. Finally, we provide some perspectives for future works.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1908.03068 [pdf]
PRC(2020)·8 citations
06
[Submitted on 8 Aug 2019]
Sum Rule of Femtoscopic Correlation Function
Radoslaw Maj🇵🇱 · Stanislaw Mrowczynski🇵🇱
A correlation function of two particles with small relative velocities obeys a sum rule - the momentum integral of the function is determined due to the completeness of quantum states of the particles. The original sum rule derived in 1995 suffered from a serious problem: the momentum integral was ultraviolet divergent in physically interesting cases. We resolve the problem by considering the sum rule not of a single correlation function but of a sum or difference of two appropriately chosen correlation functions. The improved sum rule is shown to work well for the exact Coulomb correlation functions. We argue that the sum rule can be used to test an accuracy and range of applicability of correlation functions computed in approximate models. The neutron-proton correlation function is discussed as an example.
Comments:
9 pages, 8 figures, to appear in Phys. Rev. C
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1908.03178 [pdf]
PRC(2020)·5 citations

Affiliations

first authorsco-authorsvia INSPIRE

Chiral crossover characterized by Mott transition at finite temperature

Neutron skins of heavy nuclei and tidal deformability of neutron star

Viscous coefficients and thermal conductivity of a πKN gas mixture in the medium

Kinetic freeze-out in central heavy-ion collisions between 7.7 and 2760 GeV per nucleon pair

A first step in the nuclear inverse Kohn-Sham problem: from densities to potentials

Sum Rule of Femtoscopic Correlation Function

Affiliations

Viscous coefficients and thermal conductivity of a $π K N$ gas mixture in the medium