Nuclear Theory·nucl-th

Thursday·July 31, 2025

9 papers—1 primary·8 cross-listed

01
The influence of electromagnetic fields on the generation of the directed and elliptic flows of heavy quark in relativistic heavy-ion collisions
Santosh K. Das🇮🇳 · Olga Soloveva🇩🇪 · Taesoo Song🇩🇪 · Elena Bratkovskaya🇩🇪
We study the impact of self-generated electromagnetic fields (EMF) on the charm quarks momentum evolution in the partonic and hadronic medium created in heavy-ion collisions at RHIC energy within the Parton-Hadron-String Dynamics (PHSD) off-shell transport approach. In the quark-gluon plasma (QGP) phase, the charm quark interacts with the off-shell partons whose mass and widths are given by the Dynamical Quasi-Particle Model (DQPM), which can reproduce the lattice QCD thermodynamics. The background electromagnetic fields are computed dynamically within the PHSD considering both the spectators and participants protons as well as newly produced charged hadrons, quarks, and antiquarks, which reflects naturally the electric conductivity $σ_{e l}$ of the medium. We study the directed and elliptic flow of the $D$ mesons in the presence of the electromagnetic fields. We find that electromagnetically induced splitting in the $D$ meson $v_{1}$ through $D^{0}$ and $D^{0}$ mesons is consistent with the experimental data. Furthermore, we notice that the splitting in the heavy quark $v_{1}$ as a function of $p_{T}$ is more prominent as a probe of the produced electromagnetic fields. However, we find only a small impact of electromagnetic fields on the heavy quark elliptic flow $v_{2}$ .
nucl-thhep-phnucl-exPRC(2025)·4 citations
02
Bayesian inference and jet quenching
Raymond Ehlers🇺🇸
These proceedings review the application of Bayesian inference to high momentum transfer probes of the quark--gluon plasma (QGP). Bayesian inference techniques are introduced, highlighting critical components to consider when comparing analyses. Recent calibrations using hadron observables are described, illustrating the importance of the choice of parametrization. Additional recent analyses that characterize the impact of the inclusion of jet observables, as well as soft-hard correlations, are reviewed. Finally, lessons learned from these analyses and important questions for the future are highlighted.
↳ hep-phnucl-exnucl-thEPJ Web Conf.(2025)·0 citations
03
Compositeness of near-threshold states with repulsive Coulomb interaction combined with short-range potential
Tomona Kinugawa · Tetsuo Hyodo
We investigate the internal structure of near-threshold states in a system with a repulsive Coulomb interaction combined with a short-range potential, using the compositeness. We construct a model in which the eigenmomentum is expressed in terms of three observables: the Coulomb scattering length, the Coulomb effective range, and the Bohr radius. In the presence of the Coulomb interaction, a bound state directly goes into a resonance as parameters are varied, bypassing a virtual state, in contrast to the case with only the short-range interaction. We show that the compositeness of near-threshold states can be expressed solely in terms of these observables. When the magnitude of the Coulomb effective range is much smaller than that of the Bohr radius, both shallow bound states and near-threshold resonances exhibit common structures with large compositeness, reflecting the remnant of the low-energy universality.
↳ hep-phnucl-thPoS(2026)·2 citations
04
Role of meson exchange and final-state interaction in $J / ψ$ -meson photoproduction
Sang-Ho Kim🇰🇷
We investigate $J / ψ$ photoproduction off the nucleon using a dynamical model based on a Hamiltonian framework. First, Pomeron exchange is regarded as a background contribution that accounts for the gradual rise of the total cross section with increasing beam energy. Then, the meson-exchange and direct $J / ψ$ -radiation contributions are included as part of the Born term. More specifically, we examine the contributions of the light-meson [ $π^{0} (135)$ , $η (548)$ , $η^{'} (958)$ , $f_{1} (1285)$ ] and charmonium-meson [ $η_{c} (1 S)$ , $χ_{c 0} (1 P)$ , $χ_{c 1} (1 P)$ , $η_{c} (2 S)$ , $χ_{c 1} (3872)$ ] exchanges in the $t$ -channel diagram. Most of the coupling constants are determined from the radiative decays of the $J / ψ$ or other relevant charmonium states. Finally, we consider the $J / ψ N$ final-state interaction (FSI) within the leading-order approximation, which includes gluon-exchange and direct $J / ψ N$ -coupling terms. The model parameters of the Hamiltonian are fitted to the data from the GlueX and $J / ψ$ -007 experiments at Jefferson Laboratory (JLab). The light mesons $η (548)$ and $η^{'} (958)$ are found to make the most significant contributions, whereas the charmonium mesons play only a minor role. The direct $J / ψ$ -radiation term begins to come into play only in the backward scattering regions. The FSI contribution is suppressed by a factor of $1 0^{1} - 1 0^{2}$ in comparison to the Born-term contribution when a Yukawa-type potential is employed for the charmonium-nucleon interaction. Our results agree well with the available JLab data on the total and $t$ -dependent differential cross sections. High-precision, angle-dependent data in the threshold region ( $E_{γ} ⩽ 8.9$ GeV) are crucial for confirming the FSI effect.
↳ hep-phnucl-thPoS(2026)·0 citations
05
Kaon-deuteron femtoscopy from unitarized chiral interactions
Àngels Ramos🇪🇸 · Juan M. Torres-Rincon🇪🇸 · Alejandro de Fagoaga🇪🇸 · Esteve Cabré🇪🇸
We have performed a theoretical study of the correlation functions of $K^{-} d$ and $K^{+} d$ pairs and compared them with those provided by the ALICE Collaboration from Pb-Pb collisions, and also from high-multiplicity p-p collisions in the case of $K^{+} d$ . In addition to implementing the effect of the Coulomb force, the $K^{-} d$ and $K^{+} d$ wave functions are derived from the corresponding strong scattering amplitudes that are built employing a unitarized chiral model for the elementary $K^{-} N$ and $K^{+} N$ interactions. We present results for the impulse approximation, which accounts for single-scattering processes of the kaon with the nucleons of the deuteron, as well as for the solution of the Faddeev equations in the so-called fixed center approximation, which includes multiple rescattering effects. The $K^{-} d$ correlation function is shown to be very sensitive to both the size of the source and the relative momentum of the interacting pair, with large deviations from the Coulomb baseline and sizable multi-step scattering contributions, effects that are tied to a $K ˉ N$ strong interaction that is dominated by the influence of the subthreshold resonance $Λ (1405)$ . In contrast, the $K^{+} d$ correlation function only differs appreciably from the Coulomb one for relatively small sources, reflecting the mildly repulsive and elastic behavior of the $K N$ strong force. The calculated correlation functions are found to nicely reproduce the experimental data of the ALICE collaboration. Our study serves to reinforce the validity of the theoretical models employed and demonstrates the value of femtoscopy as a powerful tool for probing hadronic interactions involving strangeness.
↳ hep-phnucl-exnucl-thPRD(2026)·8 citations
06
Distorted quarkonia and spin alignment
Guowei Yan🇨🇳 · Shu Lin🇨🇳
It is well-known that atoms can change their shape when subject to external electromagnetic fields. Analogous phenomenon is expected for particles, which are much smaller in size with the corresponding shape change much harder to observe. We point out that shape change of particles can be accessed by measurements of their spin alignment. Motivated by recent measurements of spin alignment in relativistic heavy ion collisions, we consider quarkonia in electromagnetic fields as an example. We show that the quarkonia spin alignment receives both spin contribution from spin states mixing and orbital contribution from shape change. By a proper choice of quantization axis, it is possible to switch off the spin contribution, leaving only the orbital contribution. This makes spin alignment measurement a valuable probe of quarkonium structure.
↳ hep-phnucl-exnucl-thPRD(2026)·3 citations
07
Entanglement suppression and emergent symmetries in hadron scatterings
Tao-Ran Hu · Su Chen · Katsuyoshi Sone · Feng-Kun Guo · Tetsuo Hyodo · Ian Low
Recently entanglement suppression was proposed to be one potential origin of emergent symmetries. In this work, we extend this theoretical framework to accommodate particles with arbitrary spins and/or arbitrary group representations. As case studies, we discuss recent efforts to test the entanglement-suppression conjecture in two hadron systems that exhibit possible emergent symmetries. The first concerns interactions involving spin-3/2 baryons, where entanglement suppression gives rise to symmetries such as $SU (40)$ spin-flavor symmetry. The second system involves low-energy scattering of heavy mesons, where entanglement suppression leads to an enhancement of the inherent heavy-quark spin symmetry to a light-quark spin symmetry, predicting additional siblings for the prominent exotic double-charm meson $T_{cc} (3875)^{+}$ . These predictions should be confronted against experimental data and lattice results to further test the minimal-entanglement conjecture.
↳ hep-phhep-thnucl-thquant-phPoS(2026)·8 citations
08
Quantum Simulation of Nuclear Dynamics in First Quantization
Luca Spagnoli🇮🇹 · Chiara Lissoni🇮🇹 · Alessandro Roggero🇮🇹
The study of real time dynamics of nuclear systems is of great importance to provide theoretical predictions of cross sections relevant for both terrestrial experiments as well as applications in astrophysics. First principles simulations of these dynamical processes is however hindered by an exponential cost in classical resources and the possibility of performing scalable simulations using quantum computers is currently an active field of research. In this work we provide the first complete characterization of the resource requirements for studying nuclear dynamics with the full Leading Order (LO) pionless EFT Hamiltonian in first quantization employing simulation strategies using both product formulas as well as Quantum Signal Processing. In particular, we show that time evolution of such an Hamiltonian can be performed with polynomial resources in the number of particles, and logarithmic resources in the number of single-particle basis states. This result provides an exponential improvement compared with previous work on the same Hamiltonian model in second quantization. We find that interesting simulations for low energy nuclear scattering could be achievable with tens of millions of T gates and few hundred logical qubits suggesting that the study of simple nuclear reactions could be amenable for early fault tolerant quantum platforms.
↳ quant-phnucl-th8 citations
09
The $1/ N_{c}$ Operator Analysis of the Combined Octet and Decuplet Baryons Contact Interactions in SU(3) Chiral Effective Field Theory
Chindanai Bubpatate · Dominador F. Vaso · Jr. · Daris Samart
In this work, we construct the non-derivative four-point interactions for Octet and Decuplet baryons in the SU(3) Chiral Effective Field Theory (ChEFT) framework, and there are 104 coupling constant terms. The non-relativistic expansion of the baryon fields has been considered up to the Next-to-Leading Order (NLO) of the three-momentum expansion. We find 28 and 106 Low-Energy Constants (LECs) for Leading Order (LO) and NLO, respectively. Using the Hartree Hamiltonian of the $1/ N_{c}$ expansion of the operator product up to Next-to-Next-to-Leading Order (NNLO), we can reduce the free parameters (LECs) of the ChEFT from 134 down to 24 up to NLO of the three-momentum expansion. Moreover, we will discuss the implications of the $1/ N_{c}$ sum rules in $ΩΩ$ and $Ω N$ scatterings, where the future results from lattice QCD can be used to test our sum rules.
↳ hep-phnucl-thEPJC(2026)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE