Nuclear Theory·nucl-th

Thursday·February 27, 2025

16 papers—6 primary·10 cross-listed

07
Quarkonium Polarization Kinetic Equation from Open Quantum Systems and Effective Field Theories
Di-Lun Yang · Xiaojun Yao
Recent measurements of polarization phenomena in relativistic heavy ion collisions have aroused a great interest in understanding dynamical spin evolution of the QCD matter. In particular, the spin alignment signature of $J / ψ$ has been recently observed in Pb-Pb collisions at LHC, which may infer nontrivial spin transport of quarkonia in quark gluon plasmas. Motivated by this, we study the spin-dependent in-medium dynamics of quarkonia by using the potential nonrelativistic QCD (pNRQCD) and the open quantum system framework. By applying the Markovian approximation and Wigner transformation, we systematically derive the Boltzmann transport equation for vector quarkonia with polarization dependence in the quantum optical limit. As opposed to the previous study for the spin-independent case where the collision terms depend on chromoelectric correlators, the new kinetic equation incorporates gauge invariant correlators of chromomagnetic fields that determine the recombination and dissociation terms with polarization dependence at the order we are working in the multipole expansion. In the quantum Brownian motion limit, the Lindblad equation with new transport coefficients defined in terms of the chromomagnetic field correlators have also been derived. Our formalism is generic and valid for both weakly-coupled and strongly-coupled quark gluon plasmas. It may be further applied to study spin alignment of vector quarkonia in heavy ion collisions.
↳ hep-phnucl-thPoS(2025)·0 citations
08
Implications of {\sigma}-cut potential on Antikaon condensates in neutron stars
Prashant Thakur🇮🇳 · Yashmitha Kumaran🇲🇽 · Lakshana Sudarsan🇬🇧 · Krishna Kunnampully🇬🇧 · B. K. Sharma🇮🇳 · T. K. Jha🇮🇳
We investigate the properties of neutron stars with antikaon condensation in the framework of the Relativistic Mean-Field (RMF) model with a $σ$ -cut potential. The well-known RMF models, TM1 and TM1e, are used to analyze the structure and composition of neutron stars. The antikaon condensation part of the equation of state (EoS) is constrained from the experimental data of K $^{-}$ atomic and kaon-nucleon scattering. The $σ$ -cut potential, which is known to make the EoS stiffer at high densities, is modulated by a free parameter $f_{s}$ . Our present analysis suggests that one can obtain neutron star configurations heavier than 2 $M_{⊙}$ with antikaon condensates in most cases for $f_{s}$ = 0.6. The antikaon phase transition is a second-order for $f_{s}$ = 0.6 for both TM1 and TM1e parameter sets. The calculated global properties of neutron stars with antikaon condensates i.e., mass and radius seem to be in resonable agreement with other theoretical and observational data.
↳ astro-ph.HEgr-qchep-phnucl-thPRC(2025)·6 citations
09
A hybrid model for multi-particle production and multi-fragment emission in electron-nucleus collisions at the forthcoming Electron-Ion Collider
Ting-Ting Duan🇨🇳 · Sahanaa Büriechin🇨🇳 · Hai-Ling Lao🇨🇳 · Fu-Hu Liu🇨🇳 · Khusniddin K. Olimov🇺🇿
To present a prediction of the multi-particle production and multi-fragment emission in electron-nucleus ( $e A$ ) collisions at the forthcoming Electron-Ion Collider (EIC), a simple hybrid model which is based on the multi-source thermal model and the ideal gas model is proposed in this article. According to the hybrid model, some statistical laws such as the two-component Erlang distribution and others are presented, which means a two-source production. These statistical laws are hopeful to describe the bulk properties of multiple particles produced in the scattering of electron-nucleon ( $e N$ ) and multiple fragments emitted in the fragmentation of excited residual nucleus. Although both the scattering and fragmentation can occur in $e A$ collisions at the EIC, their two-sources are different. In $e N$ scattering, the multiple particles come from the soft excitation and hard scattering processes respectively, which are classified as two different types of events. In nuclear fragmentation, the multiple fragments come from the cold and hot sources which exist in the same excited nucleus.
↳ hep-phhep-exnucl-exnucl-thMod.Phys.Lett.A(2025)·0 citations
10
Proper effective temperature and order parameters in relativistic non-equilibrium steady states
Shin Nakamura🇯🇵 · Fuminori Okabayashi🇯🇵
We examine the concept of temperature in non-equilibrium steady states. Using the D3-D5 model of gauge/gravity duality, we investigate spontaneous symmetry breaking in a relativistic (2+1)-dimensional defect moving at constant velocity within a (3+1)-dimensional heat bath. We find that the dependence of the order parameter on both the heat bath temperature and the defect velocity can be captured by a single variable -- the proper effective temperature -- for the moving defect. Our results suggest that the proper effective temperature is an essential parameter for a class of relativistic non-equilibrium steady states.
↳ hep-thcond-mat.stat-mechnucl-thJHEP(2025)·2 citations
11
Chiral Representation of the Nucleon Mass at Leading Two-loop Order
Ze-Rui Liang🇨🇳 · Han-Xue Chen🇨🇳 · Feng-Kun Guo🇨🇳 · Zhi-Hui Guo🇨🇳 · De-Liang Yao🇨🇳
We calculate the nucleon mass in a manifestly relativistic baryon chiral perturbation theory up to the leading two-loop order. Through dimensional counting analysis, we perform the chiral expansion and verify the validity of the extended-on-mass-shell scheme at the two-loop level. As a result, we obtain the complete chiral representation of the nucleon mass up to $O (p^{5})$ , which preserves the original analytic properties and satisfies the correct power counting. The obtained chiral result is well-suited for chiral extrapolation and provides an excellent description of lattice QCD data across a broad range of pion masses. We find that the $O (p^{5})$ contribution is small, approximately $10$ MeV, and varies only mildly with increasing pion mass, demonstrating good convergence of the nucleon mass up to pion masses of about 350 MeV at two-loop order.
↳ hep-phhep-latnucl-thJHEP(2025)·8 citations
12
Higher derivative holography and temperature dependence of QGP viscosities
Thomas Apostolidis🇫🇷 · Umut Gürsoy🇳🇱 · Edwan Préau🇳🇱
Recent Bayesian analyses of heavy ion collision data have established a non-trivial temperature dependence of the shear and bulk viscosity per entropy. Motivated by this, we consider higher derivative corrections to realistic, bottom-up holographic models of quark-gluon plasma based on five-dimensional Einstein-dilaton theories and determine the dilaton potentials in the higher derivative terms by matching the Bayesian analyses. A byproduct of our analysis is the bulk viscosity that follows from the holographic V-QCD theory. Higher derivative corrections when treated perturbatively lead to tension with existing data. We investigate possible resolutions.
↳ hep-thhep-exhep-phnucl-thJHEP(2025)·4 citations
13
Chiral vortical conductivities and the moment of inertia of a rigidly rotating Fermi gas
M. Abedlou Ahadi🇮🇷 · N. Sadooghi🇮🇷
We determine the chiral vortical conductivities, as well as the orbital and spin moment of inertia of a charged, chiral, and rigidly rotating free Fermi gas. To this purpose, we begin by calculating the vacuum expectation values of a vector and axial vector current using the free fermion propagator in this medium. This propagator is derived by employing the Fock-Schwinger method based on the solutions of the Dirac equation in the presence of rotation and finite axial chemical potential. We present a complete derivation of these solutions. We demonstrate that in the first approximation, the chiral vortical conductivity associated with the vector current is proportional to the product of the vector and axial chemical potentials. In contrast, the chiral vortical conductivity related to the axial vector current depends on the temperature, the vector, and the axial vector chemical potential squares. We use the relation between the axial vector current and the angular momentum density associated with spin to determine the spin and the orbital moment of inertia of a rigidly rotating Fermi gas in a charged and chirally imbalanced medium separately. In addition, we compute the total moment of inertia by utilizing the methods presented in the first part of the paper and show that the orbital moment of inertia of a free fermion gas vanishes.
↳ hep-phcond-mat.quant-gasnucl-thPRD(2025)·5 citations
14
Topological Susceptibility in the Superconductive Phases of Quantum Chromodynamics: a Dyson-Schwinger Perspective
Fabrizio Murgana🇮🇹 · Giorgio Comitini🇮🇹 · Marco Ruggieri🇮🇹
We test non-perturbative gluon propagators recently studied in the literature, by computing the topological susceptibility, $χ$ , of the superconductive phases of Quantum Chromodynamics at high density. We formulate the problem within the High-Density Effective Theory, and use the 2-particle irreducible formalism to compute the effective potential of the dense phases. We focus on superconductive phases with two and three massless flavors. Within this formalism, we write a Dyson-Schwinger equation in the rainbow approximation for the anomalous part of the quark propagator in the superconductive phases, in which the non-perturbative gluon propagator plays its role. We complete the model by adding a $U (1)_{A}$ -breaking term whose coupling is fixed perturbatively at large quark chemical potential. We then use the effective potential to compute $χ$ in the superconductive phases. We finally discuss implications of the results for the axion mass in superdense phases of Quantum Chromodynamics.
↳ hep-phhep-thnucl-thPRD(2025)·4 citations
15
Correlation function for the $p f_{1} (1285)$ interaction
Pablo Encarnación🇪🇸 · Albert Feijoo🇪🇸 · Eulogio Oset🇪🇸
We have addressed here the problem of calculating the correlation function of a stable particle with a resonance, in particular one resonance that qualifies as a molecular state of two components. The formalism used requires to evaluate the scattering matrix of the stable particle with the molecule, a nuclear problem which we address by means of the fixed center approximation. We have applied the method to the interaction of a proton with the $f_{1} (1285)$ resonance, presently under investigation by the ALICE collaboration, where the $f_{1} (1285)$ is taken as a $K^{*} K ˉ - K ˉ^{*} K$ molecule. We find that the $p f_{1} (1285)$ interaction develops a resonance state below the $p f_{1} (1285)$ threshold, which leads to a depletion in the $p f_{1} (1285)$ correlation function for small values of the proton momentum. The discussion presented shows that these type of studies can provide much information on the nature of some resonances and the existence of three-body bound states involving mesons and baryons.
↳ hep-phnucl-thPRD(2025)·13 citations
16
Work and heat exchanged during sudden quenches of strongly coupled quantum systems
Zohreh Davoudi · Christopher Jarzynski · Niklas Mueller · Greeshma Oruganti · Connor Powers · Nicole Yunger Halpern
How should one define thermodynamic quantities (internal energy, work, heat, etc.) for quantum systems coupled to their environments strongly? We examine three (classically equivalent) definitions of a quantum system's internal energy under strong-coupling conditions. Each internal-energy definition implies a definition of work and a definition of heat. Our study focuses on quenches, common processes in which the Hamiltonian changes abruptly. In these processes, the first law of thermodynamics holds for each set of definitions by construction. However, we prove that only two sets obey the second law. We illustrate our findings using a simple spin model. Our results guide studies of thermodynamic quantities in strongly coupled quantum systems.
↳ quant-phcond-mat.stat-mechhep-lathep-ph+1PRE(2026)·10 citations

Affiliations

first authorsco-authorsvia INSPIRE