Nuclear Theory·nucl-th

Wednesday·December 22, 2021

10 papers—4 primary·6 cross-listed

01
[Submitted on 21 Dec 2021]
A study of the elastic $π N$ scattering at finite baryon density
Hyeon-dong Han🇰🇷 · Parada T. P. Hutauruk🇰🇷 · Seung-il Nam🇰🇷
We investigate the elastic $π N$ scattering for the $I = 3/2$ channel dominated by the $Δ (1232)$ resonance at finite baryon density $ρ_{B}$ for the symmetric nuclear matter, employing the effective Lagrangian approach at the tree-level Born approximation. The quark-meson coupling (QMC) model and linear-density approximation are employed to describe the medium modifications for the in-medium baryon properties, such as the nucleon and $Δ$ masses, and $Δ$ full decay width. We first reproduce the experimental data in vacuum by fitting the model parameters, then analyze various physical observables including total and differential cross sections, proton-spin asymmetry in medium. It turns out that the $Δ$ -resonance contribution becomes diminished with respect to $ρ_{B}$ , due to the weaker $π N$ -interaction strength in medium. Beyond the $Δ$ -resonance region $s ≳ 1.5$ GeV, the cross sections are almost independent of the density. The present results will be useful to understand the role of the $Δ$ resonance in the neutron-star equation of state (EoS) as well as in relativistic heavy-ion collision experiments.
Comments:
11 pages, 15 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2112.11060 [pdf]
Mod.Phys.Lett.A(2022)·3 citations
02
[Submitted on 21 Dec 2021]
A study of shear viscosity coefficient of quark matter in Polyakov quark meson model for three flavors
Ritesh Ghosh🇮🇳
We have computed shear viscosity coefficient for hot and dense QCD matter within Polyakov loop extended quark meson(PQM) model for three flavors. Viscosity coefficient is estimated using Boltzmann equation within the relaxation time approximation. Relaxation times for quarks are calculated from elastic scattering of quarks and antiquarks via gluon exchange. Also the mean free paths of strange and light quarks are estimated for this cases. The calculations are performed at finite chemical potential. Thermodynamic properties like energy, pressure, entropy densities are also computed and compared with lattice QCD data.
Comments:
14 pages, 5 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2112.11103 [pdf]
0 citations
03
[Submitted on 21 Dec 2021]
Nuclear configurational entropy and high energy hadron-hadron scattering reactions
G. Karapetyan🇧🇷
In this work, the high energy hadron-hadron scattering is studied in the framework of holographic AdS/QCD models, using the Brower-Polchinski-Strassler-Tan Pomeron exchange kernel and gravitational form factors. We apply the configurational entropy techniques to estimate the slope of the total cross section for the total hadron-hadron cross sections at high energies. A good agreement is derived between our approach and the total cross section for combinations that include the pion-nucleon, nucleon-nucleon, and pion-pion, as well as for any high energy data with inclusion of data from the TOTEM collaboration at the LHC and approximated by the Pomeron exchange. In the case of pion-nucleon and pion-pion scattering, the agreement for the critical points to the differential configurational entropy can be reached within 1.1% even without the involvement of any extra parameters.
Comments:
1 figure
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2112.11359 [pdf]
Eur.Phys.J.Plus(2022)·12 citations
04
[Submitted on 21 Dec 2021]
Model-Independent Determination of Isotopic Cross Sections per Fission for Reactor Antineutrinos
Yu-Feng Li🇨🇳 · Zhao Xin🇨🇳
Model-independent reactor isotopic cross sections per fission are determined by global fits of the reactor antineutrino data from High-Enriched Uranium (HEU) reactor rates, Low-Enriched Uranium (LEU) reactor rates, and reactor fuel evolution data. Taking account of the implicit quasi-linear relationship between the fission fractions of $^{239} Pu$ and $^{241} Pu$ in the LEU reactor data, the Inverse-Beta-Decay (IBD) yields and their correlations of the fissionable isotopes $^{235} U$ , $^{238} U$ , and Pu's are obtained. The data-driven isotopic IBD yields provide an anomaly-free model for the reactor isotopic cross sections per fission, where better than 1\% accuracy of the expected reactor IBD yields can be achieved for future experiments.
Comments:
11 pages, 4 figures. With more discussions and references added, accepted for publication at Physical Review D
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2112.11386 [pdf]
PRD(2022)·2 citations
05
[Submitted on 20 Dec 2021] (cross-list from hep-th)
Convergence of hydrodynamics in rapidly spinning strongly coupled plasma
Casey Cartwright🇺🇸 · Markus Garbiso Amano🇺🇸 · Matthias Kaminski🇺🇸 · Jorge Noronha🇺🇸 · Enrico Speranza🇺🇸
We compute the radius of convergence of the linearized relativistic hydrodynamic expansion around a non-trivially rotating strongly coupled N=4 Super-Yang-Mills plasma. Our results show that the validity of hydrodynamics is sustained and can even get enhanced in a highly vortical quark-gluon plasma, such as the one produced in heavy-ion collisions. The hydrodynamic dispersion relations are computed using a rotating background that is an analytic solution of the ideal hydrodynamic equations of motion with non-vanishing angular momentum and large vorticity gradients, giving rise to a particular boost symmetry. Analytic equations for the transport coeffcients of the rotating plasma as a function of their values in a plasma at rest are given.
Comments:
8 pages, 2 figures, comments welcome!
Subjects:
High Energy Physics — Theory (hep-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2112.10781 [pdf]
PRD(2023)·36 citations
06
[Submitted on 20 Dec 2021] (cross-list from astro-ph.HE)
Constraining neutron star properties with a new equation of state insensitive approach
Bhaskar Biswas · Sayak Datta
Instead of parameterizing the pressure-density relation of a neutron star (NS), one can parameterize its macroscopic properties such as mass ( $M$ ), radius ( $R$ ), and dimensionless tidal deformability ( $Λ$ ) to infer the equation of state (EoS) combining electromagnetic and gravitational wave (GW) observations. We present a new method to parameterize $R (M)$ and $Λ (M)$ relations, which approximate the candidate EoSs with accuracy better than 5\% for all masses and span a broad region of $M - R - Λ$ plane. Using this method we combine the $M - Λ$ measurement from GW170817 and GW190425, and simultaneous $M - R$ measurement of PSR J0030+0451 and PSR J0740+6620 to place joint constraints on NS properties. At 90 \% confidence, we infer $R_{1.4} = 12.0 5_{- 0.87}^{+ 0.98}$ km and $Λ_{1.4} = 37 2_{- 150}^{+ 220}$ for a $1.4 M_{⊙}$ NS, and $R_{2.08} = 12.6 5_{- 1.46}^{+ 1.36}$ km for a $2.08 M_{⊙}$ NS. Furthermore, we use the inferred values of the maximum mass of a nonrotating NS $M_{max} = 2.5 2_{- 0.29}^{+ 0.33} M_{⊙}$ to investigate the nature of the secondary objects in three potential neutron star-black hole merger (NSBH) system.
Comments:
Published in PRD
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
arXiv:
2112.10824 [pdf]
PRD(2022)·25 citations
07
[Submitted on 21 Dec 2021] (cross-list from hep-ph)
Towards a discovery of BSM physics from the Cabibbo angle anomaly
Chien-Yeah Seng🇩🇪
New developments in both the theories and experiments related to the extraction of the top-row Cabibbo-Kobayashi-Maskawa matrix elements $V_{u d}$ and $V_{u s}$ led to a series of new anomalies, for instance the apparent violation of the top-row unitarity relation. It is important to further reduce all the associated Standard Model theory uncertainties in order to better understand whether such observations point towards the possibility of physics beyond the Standard Model, or rather some unexpectedly large Standard Model effects. This requires improved studies of tree-level and higher-order Standard Model corrections that enter the beta decays of pions, neutron, nuclei and kaons. We will briefly review the recent progress along this direction and discuss possible improvements in the future.
Comments:
Version accepted by MPLA
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2112.10942 [pdf]
Mod.Phys.Lett.A(2022)·7 citations
08
[Submitted on 21 Dec 2021] (cross-list from hep-lat)
Searching for the BCS phase at nonzero isospin asymmetry
Bastian B. Brandt🇩🇪 · Francesca Cuteri🇩🇪 · Gergely Endrődi🇩🇪
According to perturbation theory predictions, QCD matter in the zero-temperature, high-density limits of QCD at nonzero isospin chemical potential is expected to be in a superfluid Bardeen-Cooper-Schrieffer (BCS) phase of $u$ and $d ˉ$ Cooper pairs. It is also expected, on symmetry grounds, that such phase connects via an analytical crossover to the phase with Bose-Einstein condensation (BEC) of charged pions at $μ_{I} \geq m_{π} /2$ . With lattice results, showing some indications that the deconfinement crossover also smoothly penetrates the BEC phase, the conjecture was made that the former connects continuously to the BEC-BCS crossover. We compute the spectrum of the Dirac operator, and use generalized Banks-Casher relations, to test this conjecture and identify signatures of the superfluid BCS phase.
Comments:
8 pages, 5 figures, contribution to the 38th International Symposium on Lattice Field Theory (LATTICE21)
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2112.11113 [pdf]
PoS(2022)·13 citations
09
[Submitted on 21 Dec 2021] (cross-list from astro-ph.HE)
Equation of state and neutrino transfer in supernovae and neutron stars
Kohsuke Sumiyoshi
We overview the progress of the tables of the equation of state for astrophysical simulations and the numerical methods of neutrino transfer. Hot and dense matter play essential roles in core-collapse supernovae and neutron stars. Equation of state determines the structure of compact objects and their dynamics through its behavior of thermodynamic quantities. In addition, neutrinos are trapped in supernova cores and neutron star mergers and frequently interact with matter to crucially affect dynamics in determining the explosion mechanism and the final form of compact objects. Therefore, it is essential to implement detailed processes of nuclear and neutrino physics in numerical simulations by having reliable data set of the equation of state and reaction rates. We show examples of developments of the equation of state and the neutrino transfer and discuss research directions toward understanding the explosive phenomena by the first principle calculation.
Comments:
13 pages, 4 figures; contribution to the EPJ A topical issue "CompOSE: a repository for Neutron Star Equations of State and Transport Properties"
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2112.11159 [pdf]
EPJA(2021)·4 citations
10
[Submitted on 21 Dec 2021] (cross-list from hep-lat)
Inhomogeneous phases in the chirally imbalanced $2 + 1$ -dimensional Gross-Neveu model and their absence in the continuum limit
Laurin Pannullo🇩🇪 · Marc Wagner🇩🇪 · Marc Winstel🇩🇪
We study the $μ$ - $μ_{45}$ - $T$ phase diagram of the $2 + 1$ -dimensional Gross-Neveu model, where $μ$ denotes the ordinary chemical potential, $μ_{45}$ the chiral chemical potential and $T$ the temperature. We use the mean-field approximation and two different lattice regularizations with naive chiral fermions. An inhomogeneous phase at finite lattice spacing is found for one of the two regularizations. Our results suggest that there is no inhomogeneous phase in the continuum limit. We show that a chiral chemical potential is equivalent to an isospin chemical potential. Thus, all results presented in this work can also be interpreted in the context of isospin imbalance.
Comments:
18 pages, 7 figures, 1 table; plot data provided in arXiv source; version as published in symmetry
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2112.11183 [pdf]
Symmetry(2022)·24 citations

Affiliations

first authorsco-authorsvia INSPIRE