Nuclear Theory·nucl-th

Friday·March 14, 2025

16 papers—8 primary·8 cross-listed

01
Effects of symmetry energy on the properties of hadron-quark mixed phase in hybrid stars
Min Ju🇨🇳 · Xuhao Wu🇨🇳 · Hong Shen🇨🇳
We study how the nuclear symmetry energy slope affects the properties of hadron-quark pasta phases and their sizes in massive hybrid stars ( $> 2 M_{⊙}$ ). We utilize the relativistic mean-field model with a density-dependent isovector coupling constant fitted by varying values of the symmetry energy slope $L$ to describe the hadronic matter, while the quark matter is described by a modified MIT bag model with vector interactions. We construct the hadron-quark phase transition using the energy minimization (EM) method and compare with the Gibbs construction (GC) in the hybrid star. We find that the massive hybrid stars generally tend to have a hadron-quark pasta phase core rather than a pure quark core for most values of $L$ , except in some special cases where they have a small pure quark core. Furthermore, we show that the mass and size of the pasta phase core are strongly influenced by the symmetry energy. The radius associated with the onset of pasta phases is also influenced by the symmetry energy. Additionally, we also evaluate the effects of the surface tension $σ$ , the bag constant $B$ , and the vector interaction $G_{V}$ .
nucl-thPRC(2025)·3 citations
02
$β^{-}$ -decay half-lives of even-even nuclei using the recently introduced phase space recipe
Jameel-Un Nabi · Mavra Ishfaq · Ovidiu Nitescu · Mihail Mirea · Sabin Stoica
We present the beta decay half-lives calculation for selected even even nuclei that decay through electron emission. The kinematical portion of the half-life calculation was performed using a recently introduced technique for computation of phase space factors (PSFs). The dynamical portion of our calculation was performed within the proton neutron quasiparticle random phase approximation (pn QRPA) model. Six nuclei (20O, 24Ne, 34Si, 54Ti, 62Fe, and 98Zr) were selected for the present calculation. We compare the calculated PSFs for these cases against the traditionally used recipe. In our new approach, the Dirac equation was numerically solved employing a Coulomb potential. This potential was adopted from a more realistic proton distribution of the daughter nucleus. Thus, the finite size of the nucleus and the diffuse nuclear surface corrections are taken into account. Moreover, a screened Coulomb potential was constructed to account for the effect of atomic screening. The power series technique was used for the numerical solution. The calculated values of half-lives, employing the recently developed method for computation of PSFs, were in good agreement with the experimental data.
nucl-thUniverse(2019)·4 citations
03
Non-perturbative quarkonium dissociation rates in strongly coupled quark-gluon plasma
Biaogang Wu🇺🇸 · Zhanduo Tang🇺🇸 · Ralf Rapp🇺🇸
Heavy quarks and quarkonia are versatile probes of the transport properties of the hot QCD medium produced in ultra-relativistic heavy-ion collisions (URHICs). A robust description of heavy-flavor transport coefficients requires a microscopic approach that treats the open and hidden heavy-flavor sectors on the same footing. Here, we employ the quantum many-body $T$ -matrix formalism to evaluate the dissociation rates of heavy quarkonia in the quark-gluon plasma (QGP). The basic ingredient is the heavy-light $T$ -matrix, which utilizes a nonperturbative driving kernel constrained by lattice-QCD data. Its resummation in a ladder series provides a much enhanced interaction strength compared to previously used perturbative coupling to the quasiparticle partons in the QGP. The in-medium quarkonium properties, particularly their temperature-dependent binding energies, are evaluated self-consistently using the same interaction kernel, including interference effects (also referred to as the imaginary part of the heavy-quark potential) as well as off-shell parton spectral functions. We systematically investigate the interplay of these effects and elaborate on the connections to the dipole approximation used in effective field theory.
nucl-thJHEP(2025)·11 citations
04
$γ W$ -exchange contributions in neutron $β$ decay in the forward-angle limit
Hui-Yun Cao🇨🇳 · Hai-Qing Zhou🇨🇳
In this work, the contributions from $γ W$ -exchange in neutron $β$ decay are estimated at the amplitude level. Using a general form for the electromagnetic (EM) form factors (FFs) of the proton, the EM FFs of the neutron, and the weak FFs of the $W n p$ interaction as inputs, we present analytical expressions for the inner part of the $γ W$ -exchange amplitude under the forward angle limit. The differences and relations between our method and those used in the references are discussed. To compare our numerical results with those provided in the references, we consider three types of FFs as examples. The numerical results show that when the favored EM FFs are used, our result for the contribution from the Fermi part is consistent with those reported in the references, while our results for the Gamow-Teller parts are about 7\% and 13\% larger than those reported in Ref.~\cite{Hayen-2021}.
nucl-thPRC(2025)·1 citation
05
Bayesian analysis of a (3+1)D hybrid approach with initial conditions from hadronic transport
Niklas Götz🇩🇪 · Iurii Karpenko🇨🇿 · Hannah Elfner🇩🇪
This study aims to apply statistical learning, specifically Bayesian inference, to the (3+1)D SMASH-vHLLE-hybrid model using initial conditions generated by the SMASH transport code itself, with the objective of constraining model parameters and gaining deeper insight on the temperature and baryochemical potential dependence of both the shear and the bulk viscosity. This study is performed in the hybrid approach SMASH-vHLLE, composed of the hadronic transport approach SMASH and the (3+1)D viscous hydrodynamic code vHLLE. A Bayesian framework is employed, utilizing Markov Chain Monte Carlo (MCMC) sampling to explore the parameter space. The analysis compares model predictions against experimental observables, including particle yields, momentum and flow coefficients both at midrapidity as well as in forward and backward direction. We find that the SMASH-vHLLE-hybrid framework, using hadronic initial conditions for Au+Au collisions at different beam energies, can reproduce a variety of experimental observables at midrapidity and forward/backward rapidities. Notably, the preferred posterior distribution suggests a near-vanishing specific shear viscosity in the high-temperature QGP phase, combined with moderate-to-large bulk viscosity around the phase transition region, although the constraints on baryochemical potential dependence are weak. Our findings reveal that a hadronic initial condition constrains the evolution more strictly at intermediate energies, making parameters such as the hydrodynamic onset time highly sensitive. Intriguingly, the extracted shear viscosity differs substantially from previous Bayesian analyses, motivating further systematic studies with higher-statistics data sets and refined modeling assumptions.
nucl-thhep-phnucl-exPRC(2025)·21 citations
06
Nuclear matter in relativistic Brueckner-Hartree-Fock theory with local and nonlocal covariant chiral interactions at leading order
Wei-Jiang Zou · Yi-Long Yang · Shihang Shen · Jie Meng
The simultaneous description for nuclear matter and finite nuclei has been a long-standing challenge in nuclear ab initio theory. With the success for nuclear matter, the relativistic Brueckner-Hartree-Fock (RBHF) theory with covariant chiral interactions is a promising ab initio approach to describe both nuclear matter and finite nuclei. In the description of the finite nuclei with the current RBHF theory, the covariant chiral interactions have to be localized to make calculations feasible. In order to examine the reliability and validity, in this letter, the RBHF theory with local and nonlocal covariant chiral interactions at leading order are applied for nuclear matter. The low-energy constants in the covariant chiral interactions determined with the local regularization are close to those with the nonlocal regularization. Moreover, the RBHF theory with local and nonlocal covariant chiral interactions provide equally well description of the saturation properties of nuclear matter. The present work paves the way for the implementation of covariant chiral interactions in RBHF theory for finite nuclei.
nucl-thChin.Phys.Lett.(2025)·5 citations
07
Explanation of the observed violation of isospin symmetry in relativistic nucleus-nucleus reactions
Tom Reichert🇩🇪 · Jan Steinheimer🇩🇪 · Marcus Bleicher🇩🇪
The violation of isospin symmetry in nucleus-nucleus reactions, as shown in the ratio $R_{K} = (K^{+} + K^{-}) / (K^{0} + K ˉ^{0})$ presented by NA61/SHINE, can be understood by introducing results from color-string fragmentation in $e^{+} e^{-}$ to nuclear reactions. This novel input allows for a consistent description of the $e^{+} e^{-}$ data, proton+proton data and finally nucleus-nucleus data at all investigated energies. We conclude that the observed isospin violation in nucleus-nucleus reactions is explained by asymmetric production of up- and down-quarks in the elementary color field fragmentation process.
nucl-thhep-phnucl-exPLB(2026)·7 citations
08
Apparent teleportation of indistinguishable particles
Marek Gazdzicki🇵🇱 · Daniel Kikola🇵🇱 · Ivan Pidhurskyi🇵🇱 · Leonardo Tinti🇵🇱
Teleportation, introduced in science fiction literature, is an instantaneous change of the position of a macroscopic object. Two teleportation-like phenomena have been predicted by quantum mechanics: quantum teleportation and, more recently, quantum particle teleportation. Here, we introduce the third teleportation-like phenomenon - apparent teleportation. It seems to be a natural consequence of the Standard Model's indistinguishable elementary particles and antiparticles. We illustrate the idea within a 1+1D toy model of particle-antiparticle creation and space-time evolution obeying transport locality. Furthermore, we propose a novel method to observe apparent teleportation driven by strong interactions through measurements of correlations between the momenta of charm and anticharm hadrons in nuclear collisions. Observing the apparent teleportation would uncover the basic transport properties of indistinguishable particles.
nucl-thhep-phquant-phActa Phys.Polon.B(2026)·2 citations
09
High-energy Coulomb scattering of spatially extended particles
M. L. Nekrasov🇷🇺
We analyze pure Coulomb high-energy elastic scattering of charged particles (hadrons or nuclei), discarding their strong interactions. We distinguish three scattering modes, determined by the magnitude of the momentum transfer, in which particles behave as point-like, structureless extended, and structured composite objects. The results are compared in the potential and QFT approaches of the eikonal model. In the case of proton Coulomb scattering at the LHC the difference between these two approaches is significant. This indicates the unsuitability of the potential approach. However, in the case of Coulomb scattering of heavy nuclei, the leading one is the optical approximation, which formally reproduces the prescription of the potential approach.
↳ hep-phhep-thnucl-thNPA(2025)·1 citation
10
Dominance of gluonic scale anomaly in confining pressure inside nucleon and D-term
Daisuke Fujii🇯🇵 · Mamiya Kawaguchi🇨🇳 · Mitsuru Tanaka🇯🇵
We explore the confining pressure inside the nucleon and the related gravitational form factor referred to as the D-term, using the skyrmion approach based on the scale-invariant chiral perturbation theory, where the skyrmion is described as the nucleon and a scalar meson couples to the scale anomaly through the low energy theorem. Within this model framework, the current quark mass and gluonic quantum contributions to the scale anomaly can be described by the pion and scalar meson masses, respectively, through matching with the underlying QCD. By considering the decomposition of the energy momentum tensor of nucleon, we examine the role of the scale anomaly contributions in the pressure inside the nucleon. As a result, the gluonic scale anomaly is found to dominate the confining pressure. Compared to the result based on the conventional chiral perturbation theory in the chiral limit, our result for the total pressure is capable of qualitatively improving the alignment with lattice QCD observations. Moreover, the pressure from the gluonic scale anomaly is widely distributed in position space, leading to its substantial contribution to the D-term.
↳ hep-phhep-lathep-thnucl-thPLB(2025)·25 citations
11
Improved Honeycomb and Hyperhoneycomb Lattice Hamiltonians for Quantum Simulations of Non-Abelian Gauge Theories
Marc Illa🇺🇸 · Martin J. Savage🇺🇸 · Xiaojun Yao🇺🇸
Improved Kogut-Susskind Hamiltonians for quantum simulations of non-Abelian Yang-Mills gauge theories are developed for honeycomb (2+1D) and hyperhoneycomb (3+1D) spatial tessellations. This is motivated by the desire to identify lattices for quantum simulations that involve only 3-link vertices among the gauge field group spaces in order to reduce the complexity in applications of the plaquette operator. For the honeycomb lattice, we derive a classically $O (b^{2})$ -improved Hamiltonian, with $b$ being the lattice spacing. Tadpole improvement via the mean-field value of the plaquette operator is used to provide the corresponding quantum improvements. We have identified the (non-chiral) hyperhoneycomb as a candidate spatial tessellation for 3+1D quantum simulations of gauge theories, and determined the associated $O (b)$ -improved Hamiltonian.
↳ hep-latnucl-thquant-phPRD(2025)·23 citations
12
Signs of Non-Monotonic Finite-Volume Corrections to $g_{A}$
Zack B. Hall🇺🇸 · Dimitra A. Pefkou🇺🇸 · Aaron S. Meyer🇺🇸 · Thomas R. Richardson🇺🇸 · Raúl A. Briceño🇺🇸 · M. A. Clark🇺🇸 · Martin Hoferichter🇨🇭 · Emanuele Mereghetti🇺🇸 · Henry Monge-Camacho🇺🇸 · Colin Morningstar🇺🇸 · Amy Nicholson🇺🇸 · Pavlos Vranas🇺🇸 · André Walker-Loud🇺🇸
We study finite-volume (FV) corrections to determinations of $g_{A}$ via lattice quantum chromodynamics (QCD) using analytic results and numerical analysis. We observe that $S U (2)$ Heavy Baryon Chiral Perturbation Theory does not provide an unambiguous prediction for the sign of the FV correction, which is not surprising when one also considers large- $N_{c}$ constraints on the axial couplings. We further show that non-monotonic FV corrections are naturally allowed when one considers either including explicit $Δ$ -resonance degrees of freedom or one works to higher orders in the chiral expansion. We investigate the potential impact of these FV corrections with a precision study of $g_{A}$ using models of FV corrections that are monotonic and non-monotonic. Using lattice QCD data that is approximately at the 1% level of precision, we do not see significant evidence of non-monotonic corrections. Looking forward to the next phase of lattice QCD calculations, we estimate that calculations that are between the 0.1%-1%-level of precision may be sensitive to these FV artifacts. Finally, we present an update of the CalLat prediction of $g_{A}$ in the isospin limit with sub-percent precision, $g_{A}^{QCD} = 1.2674 (96)$ .
↳ hep-lathep-phnucl-exnucl-thPRC(2026)·21 citations
13
Nucleon resonance structure to 2 GeV and the nature of the Roper
Shiryo Owa🇦🇺 · Derek B. Leinweber🇦🇺 · Anthony W. Thomas🇦🇺
The study of the spectrum of excited states of the nucleon is vital to our understanding of how QCD is realized in the baryon spectrum. Using a simultaneous analysis of the pion nucleon scattering data up to 2 GeV as well as the results of lattice QCD calculations, we obtain new insight into the nature of the Roper resonance as well as the excited states around 1.9 GeV.
↳ hep-phhep-latnucl-thPRD(2025)·12 citations
14
Exploring the multiplicity dependence of the flavor hierarchy for hadron productions in high energy pp collisions
Aogui Zhang · Xinye Peng · Liang Zheng
In this work, we perform a systematic study on the multiplicity dependence of hadron productions at mid-rapidity ( $∣ y ∣ < 0.5$ ), ranging from the light to the charm sector in pp collisions at $s = 13$ TeV. This study utilizes a multi-phase transport model (AMPT) coupled with PYTHIA8 initial conditions. We have investigated the baryon to meson ratios as well as the strange to non-strange meson ratios varying with the charged particle density. By tuning the coalescence parameters, the AMPT model provides a reasonable description to the experimental data for inclusive productions of both light and charm hadrons, comparable to the string fragmentation model calculations with color reconnection effects. Additionally, we have analyzed the relative production of hadrons by examining self-normalized particle ratios as a function of the charged hadron density. Our findings suggest that parton evolution effects and the coalescence hadronization process in AMPT model lead to a strong flavor hierarchy in the multiplicity dependence of the baryon to meson ratio. Furthermore, our investigation on the $p_{T}$ differential double ratio of baryon to meson fraction between high and low multiplicity events indicates distinct modifications to the flavor associated baryon to meson ratio $p_{T}$ shape in high multiplicity events when comparing the coalescence hadronization model to the color reconnection model. These observations highlight the importance of understanding the hadronization process in high-energy proton-proton collisions through a comprehensive multiplicity dependent multi-flavor analysis.
↳ hep-phnucl-thNucl.Sci.Tech.(2025)·5 citations
15
Hadron physics with functional methods
Gernot Eichmann🇦🇹
We give a pedagogical introduction to hadron spectroscopy and structure studies using functional methods. We explain the basic features of Dyson-Schwinger, Bethe-Salpeter and Faddeev equations, which are employed to calculate the spectra of mesons, baryons and four-quark states. We discuss dynamical mass generation as a consequence of the spontaneous breaking of chiral symmetry, which is intertwined with the emergence of the light pions as Goldstone bosons of QCD. We highlight the importance of diquark correlations in the baryon sector, while for four-quark states such as the light scalar mesons and heavy exotics the dominant two-body clusters are typically mesons. We conclude with a brief discussion of hadron matrix elements like electromagnetic form factors and how vector-meson dominance is an automatic outcome of functional equations.
↳ hep-phnucl-th23 citations
16
Chiral Magnetic Effect enhancement at lower collision energies
Sebastian Grieninger🇺🇸 · Sergio Morales-Tejera🇷🇴 · Pau G. Romeu🇪🇸
We extend previous holographic studies of the Chiral Magnetic Effect (CME) by incorporating a time-dependent magnetic field. Various magnetic field profiles proposed in the literature are implemented, and their impact on the CME signal is analyzed in both static and expanding backgrounds. Interestingly, the integrated chiral magnetic current can exhibit a non-monotonic dependence on the collision energy. Our results suggest that the CME signal is enhanced at collision energies below $s = 200$ GeV. In addition, we derive a quasi-equilibrium formula for the chiral magnetic effect in the expanding background that is valid at late times.
↳ hep-phhep-thnucl-thPRD(2025)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE