Nuclear Theory·nucl-th

Friday·December 13, 2024

12 papers—6 primary·6 cross-listed

01
Thermomagnetic Effects of Quark Matter in the NJL Model: Application of Regularization Schemes
Xiang-Qiong Liu🇨🇳
In the SU(3) Nambu-Jona-Lasinio (NJL) model of a thermally magnetized medium, the regularization methods adopted for the thermodynamic potential and the mass gap equation are utilized to calculate the relevant thermodynamic quantities in thermomagnetic quark matter. When dealing with the thermodynamic quantities and the gap equation, three schemes can be chosen, namely magnetic field-independent regularization, soft cut-off regularization, and Pauli-Villars regularization. These three regularization schemes have different influences on the properties of thermomagnetic quark matter, and different choices of regularization schemes will also lead to different effects in the calculation of the properties of thermomagnetic quark matter.
nucl-th0 citations
02
Bayesian evidence for two peaks in the sound speed in cold dense QCD
Dake Zhou🇺🇸
I show that in addition to the well-known peak inside massive neutron stars, the sound speed in cold dense QCD matter likely exhibits another peak above neutron star densities before it asymptotes to $c_{s} = C_{s} = 1/3$ . Based on the framework reported in arxiv:2408.16738, this approach does not rely on any assumption about the ultra-dense matter not realized in nature. Current multimessenger observation of neutron stars favors the two-peak scenario with a Bayes factor $5. 1_{- 0.7}^{+ 0.9}$ , where the uncertainties are systematics due to models of neutron star inner cores. This evidence grows to $2 7_{- 8}^{+ 11}$ if the $2.6 M_{⊙}$ component of GW190814 is a neutron star. The trough in $C_{s}$ separating the two peaks is inferred to be below $0.0 5_{- 0.02}^{+ 0.04}$ (at the $50%$ level) if $2.6 M_{⊙}$ neutron stars exist. The second peak above $1/3$ beyond baryon chemical potential $μ_{B} = 1.6 - 1.9$ GeV most likely signals non-perturbative effects in cold quark matter, for instance color superconductivity.
nucl-thastro-ph.HEhep-phhep-th2 citations
03
Scattering phase shifts from overlap relations in the $J$ -matrix method
Calvin W. Johnson · Bui Minh Loc · Austin Keller · Kenneth M. Nollett
The scattering problem can be implemented in a square-integrable basis via the so-called $J$ -matrix method. While methods to compute the phase shift in the $J$ -matrix approach are known, we introduce a novel formula in square-integrable bases analogous to existing integral relations or overlap integrals in a (continuous) position basis. We demonstrate the method in single-channel potential scattering. Such a result is the first step towards a more general approach to scattering and reactions in popular many-body methods such as the configuration-interaction shell model.
nucl-thphysics.atom-phPRC(2026)·0 citations
04
Exploring nuclear force with pulsar glitch observation
Zhong-Hao Tu · Ang Li
We connect nuclear forces to one of the most notable irregular behaviors observed in pulsars, already detected in approximately 6\% known pulsars, with increasingly accurate data expected from upcoming high-precision timing instruments on both ground and space. Built on Shang & Li (2021), we conduct a case study on the 2001 glitch of the Vela pulsar. For our purpose, we adopt the Relativistic Mean Field (RMF) model as the theoretical many-body framework to describe nuclear systems. We refit three representative RMF parameter sets (DD-ME2, PKDD, NL3), considering the uncertainties in nuclear matter saturation properties. Utilizing the resulting star structure, composition and nucleon properties in the medium obtained in a consistent manner, we calculate the pinning energy of superfluid vortex in the nuclear lattice in the inner crust. This leads to the evolution of associated pinning force that acts on the vortex, which can be confronted with observed glitch amplitude and short-time relaxation in the 2000 Vela glitch event, following the snowplow model of pulsar glitch. We discuss how the vortex configuration and pinning properties depend on the nuclear parameters, and find an interesting and dominant role of the nuclear symmetry energy slope on pinning strength.
nucl-thastro-ph.HEastro-ph.SRApJ(2025)·8 citations
05
Extended Skyrme effective interactions with higher-order momentum-dependence for transport models and neutron stars
Si-Pei Wang🇨🇳 · Xin Li🇨🇳 · Rui Wang🇮🇹 · Jun-Ting Ye🇨🇳 · Lie-Wen Chen🇨🇳
The recently developed extended Skyrme effective interaction based on the so-called N3LO Skyrme pseudopotential is generalized to the general N $n$ LO case by incorporating the derivative terms up to 2 $n$ th-order into the central term of the pseudopotential. The corresponding expressions of Hamiltonian density and single-nucleon potential are derived within the Hartree-Fock approximation under general nonequilibrium conditions. The inclusion of the higher-order derivative terms provides additional higher-order momentum dependence for the single-nucleon potential, and in particular, we find that the N5LO single-nucleon potential with momentum dependent terms up to $p^{10}$ can give a nice description for the empirical nucleon optical potential up to energy of $2$ GeV. At the same time, the density-dependent terms in the extended Skyrme effective interaction are extended correspondingly in the spirit of the Fermi momentum expansion, which allows highly flexible variation of density behavior for both the symmetric nuclear matter equation of state and the symmetry energy. Based on the Skyrme pseudopotential up to N3LO, N4LO and N5LO, we construct a series of interactions with the nucleon optical potential having different high-momentum behaviors and with the symmetry potentials featuring different linear isospin-splitting coefficients for nucleon effective mass, by which we study the properties of nuclear matter and neutron stars. Furthermore, within the lattice BUU transport model, some benchmark simulations with selected interactions are performed for the Au+Au collisions at a beam energy of $1.23$ GeV/nucleon, and the predicted collective flows for protons are found to nicely agree with the data measured by HADES collaboration.
nucl-thastro-ph.HEhep-phnucl-exPRC(2025)·13 citations
06
High Precision Binding Energies from Physics Informed Machine Learning
Ian Bentley · James Tedder · Marwan Gebran · Ayan Paul
Twelve physics-informed machine learning models have been trained to model binding energy residuals. Our approach begins with determining the difference between measured experimental binding energies and three different mass models. Then four machine learning approaches are used to train on each energy difference. The most successful ML technique, both in interpolation and extrapolation, is the least squares boosted ensemble of trees. The best model resulting from that technique utilizes eight physical features to model the difference between experimental atomic binding energy values in AME 2012 and the Duflo Zuker mass model. This resulted in a model that fit the training data with a standard deviation of 17 keV and that has a standard deviation of 92 keV when compared all of the values in the AME 2020. The extrapolation capability of each model is discussed, and the accuracy of predicting new mass measurements has also been tested.
nucl-thphysics.comp-phPRC(2025)·12 citations
07
Jet substructure of light and heavy flavor jets at RHIC
Zhuoheng Yang🇺🇸 · Oleh Fedkevych🇺🇸 · Roli Esha🇺🇸
Jet substructure studies at the Large Hadron Collider have been used to constrain parton distribution functions, test perturbative QCD, measure the strong-coupling constant, and probe the properties of the quark-gluon plasma. We extend these studies to lower energies at the Relativistic Heavy Ion Collider that would additionally allow us to test existing models of non-perturbative physics. In this study, we present a PYTHIA8-based Monte Carlo study of substructure of jets produced in $p + p$ collisions at 200 GeV. The selection criteria is adapted for a feasible measurement at sPHENIX. We consider different types of jet substructure observables such as jet angularities and primary Lund Plane with a special focus on suppression of collinear radiation around emitting heavy quark known as a dead cone effect.
↳ hep-phnucl-exnucl-thPRC(2026)·1 citation
08
Off-shell vertices in heavy particle effective theories and $B \to D π ℓ ν$
Michele Papucci🇺🇸 · Ryan Plestid🇺🇸
We study the modifications to decay amplitudes in heavy to heavy semileptonic decays with multiple hadrons in the final state due to intermediate heavy hadrons being off-shell or having a finite width. Combining Heavy Hadron Chiral Perturbation Theory (HH $χ$ PT) with a BCFW on-shell factorization formula, we show that these effects induce $O (1/ M)$ corrections to the standard results computed in the narrow-width approximation and therefore are important in extracting form factors from data. A combination of perturbative unitarity, analyticity, and reparameterization invariance fully determine these corrections in terms of known Isgur-Wise functions without the need to introduce new form factors. In doing so, we develop a novel technique to compute the boundary term at complex infinity in the BCFW formula for theories with derivatively coupled scalars. While we have used the $B ˉ \to D π ℓ ν$ decay as an example, these techniques can generally be applied to effective field theories with (multiple) distinct reference vectors.
↳ hep-phnucl-thJHEP(2025)·2 citations
09
Chiral phase transition: effective field theory and holography
Yanyan Bu🇨🇳 · Zexin Yang🇨🇳
We consider the chiral phase transition relevant for QCD matter at finite temperature but with vanishing baryon density. Presumably, the chiral phase transition is of second order for two-flavor QCD in the chiral limit. Near the transition temperature, we apply the Schwinger-Keldysh formalism and construct a low-energy effective field theory for the system, in which fluctuations and dissipations are systematically captured. The dynamical variables involve the chiral charge densities and order parameter (chiral condensate). Via the holographic Schwinger-Keldysh technique, the effective action is further confirmed within a modified AdS/QCD model. With higher-order terms suitably neglected, the stochastic equations derived from the effective field theory resemble those of model F in the Hohenberg-Halperin classification. Within the effective field theory, we briefly discuss the spontaneous breaking of chiral symmetry and Goldstone modes.
↳ hep-thcond-mat.mes-hallhep-phnucl-thPRD(2025)·4 citations
10
Magnetic polarisability of octet baryons near the physical quark-mass point
Thomas Kabelitz🇦🇺 · Waseem Kamleh🇦🇺 · Derek Leinweber🇦🇺
The magnetic polarisabilities of octet baryons are calculated close to the physical quark-mass point using the background field method in lattice QCD. This first calculation draws on the identification and elimination of exceptional configurations that have hindered previous attempts. The origin of the exceptional configuration problem lies in the use of a Wilson-type fermion action on electro-quenched gauge field configurations, where the dynamical-fermion gauge-field generation algorithm the electric charges of the quarks. Changes in the fermion determinant that would suppress some gauge fields in the background magnetic field are neglected, leaving improbable gauge fields that generate large additive mass renormalisations which manifest as significant outliers in correlation-function distributions. An algorithm for the systematic identification and removal of these exceptional configurations is described. We find the light up and down quarks to be problematic, particularly the up quark with its larger electric charge. The heavier mass of the strange quark protects the hyperon correlation functions to some extent. However, these also benefit from the removal of exceptional configurations. In many cases, the magnetic polarisability is calculated with good precision. We find our results to be in accord with the behaviour anticipated by chiral perturbation theory.
↳ hep-lathep-phnucl-thPRD(2025)·0 citations
11
Exploring the chiral magnetic effect in isobar collisions through Chiral Anomaly Transport
Zilin Yuan🇨🇳 · Anping Huang🇨🇳 · Guannan Xie🇨🇳 · Wen-Hao Zhou🇨🇳 · Guo-Liang Ma🇨🇳 · Mei Huang🇨🇳
We investigate the signal of the chiral magnetic effect (CME) in Au+Au collisions and isobar collisions of $_{44}^{96} Ru +_{44}^{96} Ru$ and $_{40}^{96} Zr +_{40}^{96} Zr$ in the newly developed chiral anomaly transport (CAT) module based on the state-of-the-art model a multiphase transport (AMPT). Our numerical simulation results for the ratio charge correlation $Δ γ$ in Ru+Ru and Zr+Zr collisions are close to the latest experimental data. The simulation shows that the CME signal is larger in Ru+Ru collisions than that in Zr+Zr collisions, while the background is smaller, and the upper limit of the CME signal is $15%$ in the isobar collisions.
↳ hep-phnucl-thPRC(2025)·7 citations
12
A harmonic oscillator in nonadditive statistics and a novel transverse momentum spectrum in high-energy collisions
Trambak Bhattacharyya🇵🇱 · Maciej Rybczyński🇵🇱 · Grzegorz Wilk🇵🇱 · Zbigniew Włodarczyk🇵🇱
It is widely observed that particles produced in high-energy collisions follow a power-law distribution. One such power-law distribution used extensively in the phenomenological studies owes its origin to nonadditive statistics proposed by C. Tsallis. In this article, we derive a novel nonadditive generalization of the conventional Bose-Einstein distribution using a single-mode harmonic oscillator. The approach taken in this paper eliminates the need of a regularization procedure proposed in previous works. We observe that the spectra of the bosonic particles like the pions and kaons produced in high-energy collisions are well-described by the nonadditive bosonic distribution derived in this paper.
↳ hep-phhep-exnucl-thPLB(2025)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE