Nuclear Theory·nucl-th

Thursday·May 1, 2025

11 papers—4 primary·7 cross-listed

01
Impact of isospin asymmetric nuclear medium on pseudoscalar and vector $B$ mesons
Tanisha🇮🇳 · Satyajit Puhan🇮🇳 · Navpreet Kaur🇮🇳 · Arvind Kumar🇮🇳 · Harleen Dahiya🇮🇳
In this study, using the light-front quark model, we examine how an isospin asymmetric nuclear medium affects the properties of pseudoscalar ( $B^{+}, B^{0}$ ) and vector ( $B^{*+}, B^{* 0}$ ) mesons under different temperature values and degrees of isospin asymmetry. To simulate the in-medium modifications of the constituent quark masses, we employ the chiral SU(3) quark mean field model. Our analysis focuses on evaluating the effective masses, weak decay constants, and distribution amplitudes (DAs) of $B$ mesons in isospin-asymmetric nuclear matter. The calculated vacuum values of the $B$ meson masses and decay constants show good agreement with existing experimental data, validating our approach to study the medium effects within the same framework.
nucl-thhep-phNPA(2026)·2 citations
02
Double nuclear modification factor in relativistic heavy ion collisions
A.S. Chernyshov🇷🇺 · I.P. Lokhtin🇷🇺 · A.M.Snigirev🇷🇺
The hypothesis of the factorization of the double nuclear modification factor in relativistic heavy ion collisions is tested for different types of final-state hadrons within the HYDJET++ model. The results demonstrate that this factorization holds reasonably well at moderately high transverse momenta, provided that the effects of double parton scattering can be small or neglected.
nucl-thhep-phnucl-exJETP Lett.(2025)·0 citations
03
Dilepton emission in heavy ion collisions and chemical equilibrium of QCD matter
Xiang-Yu Wu🇨🇦 · Lipei Du🇨🇦 · Charles Gale🇨🇦 · Sangyong Jeon🇨🇦
We study thermal dilepton production and anisotropic flow in Pb+Pb collisions at $s_{N N} = 5.02 TeV$ using next-to-leading-order (NLO) thermal QCD dilepton emission rates. A hybrid model (IP-Glasma+\kompost+MUSIC+UrQMD) simulates the collision evolution. The role of the pre-equilibrium stage in dilepton observables is examined. We also explore how chemical equilibrium in QCD matter affect dilepton observables.
nucl-thhep-phEPJ Web Conf.(2025)·0 citations
04
New {\em ab initio} constrained extended Skyrme equations of state for simulations of neutron stars, supernovae and binary mergers: I. Subsaturation density domain
Adriana R. Raduta · Mikhail V. Beznogov
In numerical simulations of core-collapse supernova and binary neutron stars mergers, information about the energetics and composition of matter is implemented via external tables covering the huge ranges of thermodynamic conditions explored during the astrophysical evolution. More than 120 general-purpose equation of state (EOS) tables have been contributed so far. Unfortunately, not all of them comply with current constraints from theoretical and experimental nuclear physics and astrophysical observations of neutron stars. Systematic investigations of the role that dense matter properties play in the evolution of these astrophysical phenomena require that more EOS tables are provided. We build a set of general-purpose EOS tables. At zero temperature, they comply with all currently accepted constraints, including {\em ab initio} chiral effective field theory calculations of pure neutron matter. This set is designed to explore a wide variety of the behaviors of the effective masses as functions of density, which is reflected into a wide range of thermal behaviors. We employ Brussels extended Skyrme interactions generated by means of Bayesian inference techniques. An extended nuclear statistical equilibrium model is developed for modeling sub-saturated inhomogeneous nuclear matter (NM). Here, we study the properties of sub-saturated inhomogeneous NM over wide ranges of density, temperature, and proton fraction. We analyze in detail the mechanisms of transition to homogeneous matter and estimate the transition density. Our key results include a thick layer of neutron rich isotopes of He or H in the inner crusts of neo-neutron stars, significant abundance of exotic isotopes of H and He in warm and neutron-rich matter and a detailed study of the thermodynamic stability of cold stellar matter. The EOS tables are publicly available in the \textsc{CompOSE} online database.
nucl-thastro-ph.HEAstron.Astrophys.(2025)·6 citations
05
Neutrino-antineutrino synchrotron emission from magnetized dense quark matter
Ritesh Ghosh🇺🇸 · Igor A. Shovkovy🇺🇸
Using the Kadanoff-Baym formalism, we perform a detailed study of neutrino-antineutrino synchrotron emission from strongly magnetized, dense quark matter under conditions relevant to compact stars. Starting from an exact expression for the emission rate that fully accounts for Landau-level quantization of quarks, we derive an approximate formula applicable in the regime where quark chemical potentials are much larger than all other relevant energy scales. We demonstrate that the emission rate is largely controlled by a single dimensionless ratio between two low-energy scales: the Landau-level spacing at the Fermi surface, $∣ e_{f} B ∣/ μ_{f}$ , and the temperature of the quark matter, $T$ . When the ratio $∣ e_{f} B ∣/ (μ_{f} T)$ approaches zero, many closely spaced Landau levels contribute to the emission, but the total rate vanishes as $B \to 0$ . In the opposite limit, where the ratio is large, the rate is dominated by transitions between adjacent levels and is exponentially suppressed due to Landau-level quantization, which limits the thermal activation of quarks near the Fermi surface. Our results show that, even in the presence of the strongest magnetic fields expected in compact stars, the synchrotron emission remains suppressed by more than 3 orders of magnitude compared to the direct Urca process. This implies that such emission is unlikely to play any substantial role in the cooling of magnetized quark stars, at least those made of unpaired quark matter phases.
↳ hep-phastro-ph.HEnucl-thPRD(2025)·3 citations
06
Universal Equilibration Condition for Heavy Quarks
Krishna Rajagopal🇺🇸 · Bruno Scheihing-Hitschfeld🇺🇸 · Urs Achim Wiedemann🇨🇭
Kinetic equilibration at late times is physically required for heavy particles in a finite temperature medium. In Fokker-Planck dynamics, it is ensured by the Einstein relation between the drag and longitudinal momentum diffusion coefficients. However, in certain gauge field theories, this relation is violated at any nonzero heavy quark velocity. Recent work in strongly coupled $N = 4$ SYM gauge theory shows that the Kolmogorov equation for the heavy quark phase space distribution (that reduces to Fokker-Planck form upon truncating the momentum transfer probability distribution to second moments) does equilibrate even though the Fokker-Planck equation does not. Going beyond these (to date theory-specific) insights, we derive a universal equilibration condition for the kernel of the Kolmogorov equation and, consequently, for the momentum transfer probability distribution that holds in any quantum field theory with any coupling strength. This condition, which is the generalization of the Einstein relation to quantum field theories which feature non-Gaussian fluctuations, reveals that the asymmetry between energy loss and energy gain in the momentum transfer probability distribution takes a simple, theory-independent, form.
↳ hep-phhep-thnucl-thPRL(2025)·14 citations
07
Quarkonium suppression in strongly coupled plasmas
Bruno Scheihing-Hitschfeld🇺🇸 · Xiaojun Yao🇺🇸
Suppression of open heavy quarks and quarkonia in heavy-ion collisions are among the most informative probes of quark-gluon plasma (QGP). Interpreting the full wealth of data obtained from the collision events requires a precise theoretical understanding of the evolution of heavy quarks and quarkonia as they propagate through a strongly coupled plasma. Such calculations require the evaluation of a gauge-invariant correlator of chromoelectric fields. This chromoelectric correlator encodes all the characteristics of QGP that the dissociation and recombination dynamics of quarkonium are sensitive to, which is to say can in principle measure. We review its distinctive qualitative features at weak coupling in QCD up to next-to-leading order and at strong coupling in $N = 4$ SYM using the AdS/CFT correspondence, as well as its formulation in Euclidean QCD. Furthermore, we report on recent progress in applying our results to the calculation of the final quarkonium abundances after propagating through a cooling droplet of QGP, which illustrates how we may learn about QGP from quarkonium measurements. We devote special attention to how the presence of a strongly coupled plasma modifies the transport description of quarkonium, in comparison to approaches that rely on weak coupling approximations to describe quarkonium dissociation and recombination.
↳ hep-phnucl-thEPJ Web Conf.(2025)·0 citations
08
Analysis of $Σ^{*}$ via isospin selective reaction $K_{L} p \to π^{+} Σ^{0}$
Dan Guo🇨🇳 · Jun Shi🇨🇳 · Igor Strakovsky🇺🇸 · Bing-Song Zou🇨🇳
The isospin-selective reaction $K_{L} p \to π^{+} Σ^{0}$ provides a clean probe for investigating $I = 1$ $Σ^{*}$ resonances. In this work, we perform an analysis of this reaction using an effective Lagrangian approach for the first time, incorporating the well-established $Σ (1189) 1/ 2^{+}$ , $Σ (1385) 3/ 2^{+}$ , $Σ (1670) 3/ 2^{-}$ , $Σ (1775) 5/ 2^{-}$ states, while also exploring contributions from other unestablished states. By fitting the available differential cross section and recoil polarization data, adhering to partial-wave phase conventions same as PDG, we find that besides the established resonances, contributions from $Σ (1660) 1/ 2^{+}$ , $Σ (1580) 3/ 2^{-}$ and a $Σ^{*} (1/ 2^{-})$ improve the description. Notably, a $Σ^{*} (1/ 2^{-})$ resonance with mass around 1.54 GeV, consistent with $Σ (1620) 1/ 2^{-}$ , is found to be essential for describing the data in this channel, a stronger indication than found in previous analyses focusing on $π Λ$ final states. While providing complementary support for $Σ (1660) 1/ 2^{+}$ and $Σ (1580) 3/ 2^{-}$ , our results highlight the importance of the $Σ (1620) 1/ 2^{-}$ region in $K_{L} p \to π^{+} Σ^{0}$ . Future high-precision measurements are needed to solidify these findings and further constrain the $Σ^{*}$ spectrum.
↳ hep-phnucl-thPRD(2025)·5 citations
09
Physics-Informed Priors Improve Gravitational-Wave Constraints on Neutron-Star Matter
Spencer J. Magnall🇦🇺 · Christian Ecker🇩🇪 · Luciano Rezzolla🇩🇪 · Paul D. Lasky🇦🇺 · Simon R. Goode🇦🇺
Gravitational-wave astronomy shows great promise in determining nuclear physics in a regime not accessible to terrestrial experiments. We introduce physics-informed priors constrained by nuclear theory and perturbative Quantum Chromodynamics calculations, as well as astrophysical measurements of neutron-star masses and radii. When these priors are used in gravitational-wave astrophysical inference, we show a significant improvement on nuclear equation of state constraints. Applying these to the first observed gravitational-wave binary neutron-star merger GW170817, the constraints on the radius of a $1.4 M_{⊙}$ neutron star improve from $R_{1.4} = 12.5 4_{- 1.54}^{+ 1.05} km$ to $R_{1.4} = 12.1 1_{- 1.11}^{+ 0.91} km$ and those on the tidal deformability from $Λ ~_{1.186} < 720$ to $Λ ~_{1.186} = 38 4_{- 158}^{+ 306}$ ( $90%$ confidence intervals) at the events measured chirp mass $M = 1.186 M_{⊙}$ . We also show these priors can be used to perform model selection between binary neutron star and neutron star-black hole mergers; in the case of GW190425, the results provide only marginal evidence with a Bayes factor $B F = 1.33$ in favour of the binary neutron star merger hypothesis. Given their ability to improve the astrophysical inference of binary mergers involving neutron stars, we advocate for these physics-informed priors to be used as standard in the literature and provide open-source code for reproducibility and adaptation of the method.
↳ astro-ph.HEgr-qcnucl-thApJL(2025)·9 citations
10
Dynamical Local Tadpole-Improvement in Quantum Simulations of Gauge Theories
Marc Illa🇺🇸 · Martin J. Savage🇺🇸 · Xiaojun Yao🇺🇸
We identify a new element in quantum simulations of lattice gauge theories, arising from spacetime-dependent quantum corrections in the relation between the link variables defined on the lattice and their continuum counterparts. While in Euclidean spacetime simulations, based on Monte Carlo sampling, the corresponding tadpole improvement leads to a constant rescaled value per gauge configuration, in Minkowski spacetime simulations it requires a state- and time-dependent update of the coefficients of operators involving link variables in the Hamiltonian. To demonstrate this effect, we present the results of numerical simulations of the time evolution of truncated SU(2) plaquette chains and honeycomb lattices in 2+1D, starting from excited states with regions of high energy density, and with and without entanglement.
↳ quant-phhep-latnucl-th11 citations
11
Thermoelectric Thomson coefficient of quark-gluon plasma in the presence of a time-varying magnetic field
Kamaljeet Singh🇮🇳 · Raghunath Sahoo🇮🇳
Heavy-ion collision experiments such as the Large Hadron Collider and the Relativistic Heavy Ion Collider offer a unique platform to study several key properties of the quark-gluon plasma (QGP), a deconfined state of strongly interacting matter. Quarks, being the electrically charged particles, can induce an electric current in the medium in response to the temperature gradients. Hence, the QGP medium can behave like a thermoelectric medium. The thermoelectric coefficients, such as the Seebeck and Thomson coefficients, can help us to understand the intricate transport phenomenon of the medium. In peripheral collisions, the intense, transient, and time-dependent magnetic field created due to spectator protons significantly influences the thermoelectric properties of the QGP medium, affecting the charge and heat transport. This work uses the quasi-particle model to calculate the Thomson coefficient in QGP. The Thomson effect, describing the continuous heating or cooling of the charge-carrying medium in the presence of temperature gradients, remains largely unexplored in QGP. The Seebeck effect, which relates temperature gradients to induced electric fields, has been widely studied in the literature. For the first time, we calculate the magneto-Thomson and transverse Thomson coefficients. We have studied their dependence on temperature, baryon chemical potential, center of mass energy, and time-dependent magnetic field with different decay parameters. The transverse Thomson effect originates due to the presence of the Nernst effect in the presence of a magnetic field. Our results provide new insights into the higher-order thermoelectric transport properties of the QGP medium in the context of heavy-ion collisions.
↳ hep-phhep-exhep-thnucl-ex+1PRD(2025)·7 citations

Affiliations

first authorsco-authorsvia INSPIRE