Nuclear Theory·nucl-th

Tuesday·October 8, 2024

12 papers—5 primary·7 cross-listed

01
[Submitted on 5 Oct 2024]
Kubo formula for spin hydrodynamics: spin chemical potential as leading order in gradient expansion
Sourav Dey🇮🇳 · Arpan Das🇮🇳
We present a first-order dissipative spin hydrodynamic framework, where the spin chemical potential $ω^{μν}$ is treated as the leading term in the hydrodynamic gradient expansion, i.e., $ω^{μν} \sim O (1)$ . We argue that for the consistency of the theoretical framework, the energy-momentum tensor needs to be symmetric at least up to order $O (\partial)$ . We consider the phenomenological form of the spin tensor, where it is anti-symmetric in the last two indices only. A comprehensive analysis of spin hydrodynamics is conducted using both macroscopic entropy current analysis and microscopic Kubo formalism, establishing consistency between the two approaches. A key finding is the entropy production resulting from spin-orbit coupling, which alters the traditional equivalence between the Landau and Eckart fluid frames. Additionally, we identify cross-diffusion effects, where vector dissipative currents are influenced by gradients of both spin chemical potential and chemical potential corresponding to the conserved charge through off-diagonal transport coefficients. Two distinct methods for decomposing the spin tensor are proposed, and their equivalence is demonstrated through Kubo relations.
Comments:
25 pages, No figures, Comments are welcome
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th)
arXiv:
2410.04141 [pdf]
PRD(2025)·21 citations
02
[Submitted on 5 Oct 2024]
Peak of sound velocity, scale symmetry, and nuclear force in baryonic matter
Lu-Qi Zhang🇨🇳 · Yao Ma🇨🇳 · Yong-Liang Ma🇨🇳
The sound velocity in homogeneous matter has fundamental significance as it relates to the stiffness of the equation of state of compact star matter. In this work, we investigate the density evolution of the sound velocity in homogeneous {neutron matter at zero temperature} by using an effective field theory implemented with a conformal compensator -- the nonlinear realization of scale symmetry -- regarded as the source of the lightest scalar meson. We find that the peak of sound velocity emerges naturally in the intermediate density region, $(1 - 2.5) n_{0}$ , without resorting to any transitions from hadron to exotic configurations or introducing new degrees of freedom. This phenomenon is not found in the Walecka-type models where the sigma meson is included in the linear-type approach, therefore it is an intrinsic character of the dilaton compensator approach through the matching of the QCD trace anomaly; a mechanism has not been found before, and it connects to the character of the lightest scalar meson. In addition, these observations shed light on how the hidden scale symmetry manifests in the nuclear medium from the unitarity limit in dilute matter to the dilaton limit in compact star matter.
Comments:
Published version
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2410.04142 [pdf]
PRC(2025)·11 citations
03
[Submitted on 6 Oct 2024]
Phase Diagrams of Relativistic Selfinteracting Boson System
V. Gnatovskyy🇺🇦 · D. Anchishkin🇺🇦 · D. Zhuravel🇺🇦 · V. Karpenko🇺🇦
Within the Canonical Ensemble, we investigate a system of interacting relativistic bosons at finite temperatures and finite isospin densities in a mean-field approach. The mean field contains both attractive and repulsive terms. Temperature and isospin-density dependencies of thermodynamic quantities were obtained. It is shown that in the case of attraction between particles in a bosonic system, a liquid-gas phase transition develops against the background of the Bose-Einstein condensate. The corresponding phase diagrams are given. We explain the reasons why the presence of a Bose condensate significantly increases the critical temperature of the liquid-gas phase transition compared to that obtained for the same system within the framework of the Boltzmann statistics. Our results may have implications for the interpretation of experimental data, in particular, how sensitive the critical point of the mixed phase is to the presence of the Bose-Einstein condensate.
Comments:
27 pages, 22 figures. arXiv admin note: text overlap with arXiv:2102.02529
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Quantum Physics (quant-ph)
arXiv:
2410.04580 [pdf]
Ukr.J.Phys.(2024)·1 citation
04
[Submitted on 7 Oct 2024]
Probing for an IR-fixed Point in QCD by Superallowed Gamow-Teller Transitions in Doubly Magic Nuclei
Mannque Rho🇫🇷 · Long-Qi Shao🇨🇳
This brief note is to point out that the recent measurements at GSI and RIKEN of the superallowed Gamow-Teller transition in the doubly magic closed-shell nucleus $^{100}$ Sn could give an indication for a possibly important {\it fundamental} quenching, thus-far unrecognized, of $g_{A}$ , unambiguously distinct from nuclear correlation effects in the framework of nuclear effective field theory. The result, either confirmed or ruled out both experimentally and theory, can have strong impacts on nuclear physics vis-à-vis with nuclear effective field theory as well as on particle physics relevant for going beyond the Standard Model.
Comments:
Revised and prepared for invited paper
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2410.04991 [pdf]
2 citations
05
[Submitted on 7 Oct 2024]
How the HESS J1731-347 event could be explained using $K^{-}$ condensation
M. Veselsky🇨🇿 · P.S. Koliogiannis🇭🇷 · V. Petousis🇨🇿 · J. Leja🇸🇰 · Ch.C. Moustakidis🇬🇷
The recent observation of a compact star with a mass of $M = 0.7 7_{- 0.17}^{+ 0.20} M_{⊙}$ and a radius of $R = 10. 4_{- 0.78}^{+ 0.86}$ km, located within the supernova remnant HESS J1731-347, has substantially reinforced the evidence for the presence of exotic matter in neutron stars core. This finding has markedly enhanced our comprehension of the equation of state for dense nuclear matter. In the present work, we investigate the possible existence of a kaon condensation in hadronic neutron stars by employing and comparing two theoretical frameworks: the Relativistic Mean Field model with first order kaon condensate and the Momentum-Dependent Interaction model complemented by chiral effective theory. To the best of our knowledge, this represents a first alternative attempt aimed to explain the bulk properties of the specific object with the inclusion of a kaon condensation in dense nuclear matter. The application of two different models enriches the research, providing insights from the aspect of different theoretical frameworks that accurately predict the existence of HESS J1731-347. In both cases significant insights are extracted for the parameter space of models, emphasizing to those concerning the nucleon-kaon potential, the threshold density for the appearance of a kaon condensation, as well as the parameter $a_{3} m_{s}$ which is related to the strangeness content of the proton. Concluding, the present research indicates that a more systematic investigation of similar objects could offer valuable constraints on the properties of dense nuclear matter.
Comments:
v1: 9 pages, 7 figures, 1 table. v2: 9 pages, 7 figures, 1 table, updated text; accepted for publication in Physics Letters B
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
arXiv:
2410.05083 [pdf]
PLB(2025)·14 citations
06
[Submitted on 3 Oct 2024] (cross-list from hep-ph)
Accessing Generalized Parton Distributions through $2 \to 3$ exclusive processes
Goran Duplančić🇫🇷 · Saad Nabeebaccus🇭🇷 · Kornelija Passek-K.🇫🇷 · Bernard Pire🇭🇷 · Lech Szymanowski🇫🇷 · Samuel Wallon🇵🇱
We review our results on a new class of $2 \to 3$ exclusive processes, as a probe of both chiral-even and chiral-odd quark GPDs. We consider the exclusive photoproduction of a photon-meson pair, in the kinematics where the pair has a large invariant mass, described in the collinear factorization framework. We cover the whole kinematical range from medium energies in fixed target experiments to very large energies of colliders, by considering the experimental conditions of JLab 12-GeV, COMPASS, future EIC and LHC (in ultra-peripheral collisions) cases. Our analysis covers neutral and charged rho-mesons, as well as charged pions. The case of the rho-meson, depending on its polarization, provides access to either chiral-even or chiral-odd GPDs, at leading twist. We find that the order of magnitude of the obtained cross sections are sufficiently large for a dedicated experimental analysis to be performed, especially at JLab. Furthermore, we compute the linear photon beam polarization asymmetry, which we find to be sizeable, in the case of a longitudinally polarized $ρ$ -meson or of a charged pion. These predictions are obtained for both asymptotic distribution amplitude (DA) and holographic DA.
Comments:
7 pages, 1 figure, Presented by S. Wallon at the 31st International Workshop on Deep Inelastic Scattering (DIS2024). arXiv admin note: substantial text overlap with arXiv:2401.17656
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2410.03793 [pdf]
PoS(2025)·0 citations
07
[Submitted on 4 Oct 2024] (cross-list from hep-ph)
Impressions of Parton Distribution Functions
Yang Yu🇨🇳 · Craig D. Roberts🇨🇳
Parton distribution functions (DFs) have long been recognised as key measures of hadron structure. Today, theoretical prediction of such DFs is becoming possible using diverse methods for continuum and lattice analyses of strong interaction (QCD) matrix elements. Recent developments include a demonstration that continuum and lattice analyses yield mutually consistent results for all pion DFs, with behaviour on the far valence domain of light-front momentum fraction that matches QCD expectations. Theory is also delivering an understanding of the distributions of proton mass and spin amongst its constituents, which varies, of course, with the resolving scale of the measuring probe. Aspects of the pion DF and proton spin developments are sketched herein, along with some novel perspectives on gluon and quark orbital angular momentum.
Comments:
9 pages, 3 figures, 1 table. Review/perspective commissioned and accepted by Chin. Phys. Lett
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:
2410.03966 [pdf]
Chin.Phys.Lett.(2024)·21 citations
08
[Submitted on 5 Oct 2024] (cross-list from quant-ph)
Detecting spacelike vacuum entanglement at all distances and promoting negativity to a necessary and sufficient entanglement measure in many-body regimes
Boyu Gao🇺🇸 · Natalie Klco🇺🇸
Though known to be present, the accessibility of spacelike vacuum entanglement capable of being a fundamental resource for quantum information processing has remained in question at distances beyond the scale of vacuum fluctuations in massive fields. For a broad subclass of physical many-body mixed Gaussian states, including the free scalar field vacuum, the logarithmic negativity is here shown to be a necessary and sufficient measure of entanglement and to be entirely accessible by pairs of single-mode detectors in the continuum. By deriving exact and optimal detection profiles, entanglement resources in the massive field are demonstrated to be available at all distances.
Comments:
6 pages, 4 appendices, 3 figures; material promoted from appendices
Subjects:
Quantum Physics (quant-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2410.04162 [pdf]
PRA(2025)·6 citations
09
[Submitted on 5 Oct 2024] (cross-list from gr-qc)
Effect of $f (R, T)$ theory of gravity on the properties of strange quark stars
Suman Pal🇮🇳 · Gargi Chaudhuri🇮🇳
In this study, we investigate strange quark stars within the framework of modified $f (R, T)$ gravity, where $R$ represents the Ricci scalar and $T$ denotes the trace of the energy-momentum tensor, specifically defined as $f (R, T) = R + 2 χ T$ . The equation of state is obtained with the different forms of the MIT bag model and quark mass model with medium effects and self-consistent thermodynamical treatment. We find that negative values of $χ$ significantly increase both the mass and radius of the quark star. The inclusion of $χ$ helps to satisfy recent the astrophysical constraints on the mass-radius relationship. We have also constrained the values of $χ$ for each EoS, based on the observed maximum mass and corresponding radius, demonstrating that the inclusion of this parameter helps to address the challenges posed by both the GW190814 event and NICER observations of PSR J0030+0451. We also observe that the inclusion of $f (R, T)$ gravity leads to an increase in both the maximum mass, by about $(0.23 - 0.27) M_{⊙}$ , and the corresponding radius, by approximately (1.5-2.0)~\text{km}, depending on the chosen equation of state.
Subjects:
General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2410.04220 [pdf]
1 citation
10
[Submitted on 5 Oct 2024] (cross-list from hep-lat)
Persistence of charmed hadrons in QGP from lattice QCD
Sipaz Sharma🇩🇪
We study the nature of charm degrees of freedom near the chiral crossover based on lattice QCD calculations of the second and fourth-order cumulants of charm fluctuations, and their correlations with net baryon number, electric charge, and strangeness fluctuations. We show that below the chiral crossover temperature, $T_{p c}$ , the thermodynamics of charm can be very well understood in terms of charmed hadrons. We present evidence that above $T_{p c}$ , however, charm quark-like excitations emerge as new degrees of freedom contributing to the partial charm pressure. Nonetheless, up to temperatures as high as 175 MeV, charmed hadron-like excitations significantly contribute to the partial charm pressure.
Comments:
9 pages, 4 figures, Contribution to Zimanyi School Winter Workshop 2023: High Energy Heavy Ion Physics; updated based on the Referee report
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2410.04222 [pdf]
Int.J.Mod.Phys.A(2025)·4 citations
11
[Submitted on 6 Oct 2024] (cross-list from nucl-ex)
Azimuthal Anisotropy Scaling for Identified Mesons and Baryons: Insights into Medium Transport Properties, Equation of State and Hadronic Re-scattering
Roy A. Lacey (Department of Chemistry, Stony Brook University, Stony Brook, NY, USA)🇺🇸
Scaling functions for the centrality and transverse momentum dependence of $v_2(p_T,\text{cent})$ and $v_3(p_T,\text{cent})$ are constructed for identified mesons and baryons in Pb+Pb ($\sqrt{s_{NN}}=2.76,\ 5.02$~TeV), Xe+Xe (5.44~TeV), and Au+Au (0.2~TeV) collisions. These species-resolved functions capture the interplay of initial geometry, viscous attenuation, radial flow, partonic energy loss, and hadronic re-scattering across both flow- and quenching-dominated regimes. The systematic growth of the radial-flow parameter $\zeta_{\rm rf}$ with multiplicity and beam energy provides direct empirical constraints on the equation of state (EOS) of hot QCD matter. The extracted parameters also yield differential constraints on the specific shear viscosity $\eta/s$, the jet-quenching parameter $\hat{q}$, and late-stage hadronic dynamics. LHC systems exhibit low $\eta/s$, strong radial flow, and negligible re-scattering at high energy density, whereas Au+Au at RHIC energy shows even lower $\eta/s$, weaker radial flow, finite re-scattering, and reduced energy density. The coexistence of strong radial flow at low $p_T$ and significant jet suppression at high $p_T$ emerges as a defining hallmark of QGP formation, establishing the framework as a quantitative probe of QGP transport properties and EOS stiffness.
Comments:
7 pages, 4 figues, submitted for publication
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2410.04329 [pdf]
2 citations
12
[Submitted on 7 Oct 2024] (cross-list from hep-ph)
Unraveling the Energy-Energy Correlators for Heavy Flavor Tagged Jets in pp, p+Pb and Pb+Pb Collisions
Ke-Ming Shen🇨🇳 · Shi-Yong Chen🇨🇳 · Yu-Jie Huang🇨🇳 · Wei Dai🇨🇳 · Ben-Wei Zhang🇨🇳
In this study, energy-energy correlator (EEC) distributions for the $D^{0}$ , $B^{0}$ -tagged, inclusive, and the PYTHIA generated pure quark jets are computed in pp, p+Pb, and Pb+Pb collisions at \sqrts =5.02 TeV for a same jet transverse momentum interval 15-30 GeV. We find the number of particles per jet determines the height of the EEC distribution in pp baseline. The averaged energy weight distribution resulted in a shift of the originally larger angular distributed particle distribution to a smaller RL, thereby obtaining an EEC distribution. The EEC distributions for all quark-tagged jets in A+A exhibit a noticeable shift towards larger RL region, suggesting that the jets will be more widely distributed compared to those in pp collisions. The jet quenching effect will cause the pair angular distribution to shift towards larger values and increase the number of particles per jet. This redistribution of energy within the jets suggests that the already reduced jet energy is redistributed among a larger number of particles, leading to a reduced energy weight per pair. The enhancement of the number of particles per jet and the reduced averaged energy weight interplay with each other to form the medium modification of EEC.
Comments:
9 pages, 5 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2410.05081 [pdf]
3 citations

Affiliations

first authorsco-authorsvia INSPIRE