Nuclear Theory·nucl-th

Wednesday·November 13, 2024

8 papers—6 primary·2 cross-listed

01
Heavy quark potential and thermal charm production in heavy-ion collisions
Taesoo Song🇩🇪 · Jiaxing Zhao🇩🇪 · Ilia Grishmanovskii🇩🇪
Heavy quark mass in QGP is related to the heavy quark potential at a large distance. In this study we test three different heavy quark potentials, namely, the free energy, the internal energy of the heavy quark pair in QGP, and the unscreened potential, which was recently proposed by the HotQCD Collaboration, through the thermal production of charm quarks in heavy-ion collisions at the LHC. We find that the free energy potential overestimates charm production in heavy-ion collisions at the LHC, while the unscreened potential produces results closest to the experimental data from the ALICE Collaboration among the three potentials.
nucl-thhep-phEPJA(2026)·3 citations
02
Ab initio informed 20Ne(p, p $α$ )16O reaction elucidates the emergence of alpha clustering from chiral potentials
G. H. Sargsyan · Kazuki Yoshida · Kazuyuki Ogata · K. D. Launey · J. E. Escher · D. Langr · T. Dytrych
We report on the first \textit{ab initio} informed $α$ knock-out reaction in the intermediate-mass region, with the aim to probe the underlying chiral potential and its impact on the emergence of alpha clustering in this mass region. The theoretical predictions of the $α +^{16}$ O clustering in the $^{20}$ Ne ground state, based on the \textit{ab initio} symmetry-adapted no-core shell model, yield a triple differential cross section for $^{20}$ Ne(p, p $α$ ) $^{16}$ O that is in a remarkable agreement with the data. This allows us to examine predictions of surface and in-medium $α$ -cluster features from a chiral potential and to compare these to the successful antisymmetrized molecular dynamics approach.
nucl-thPLB(2025)·9 citations
03
Nonlocal interaction and collective excitation in deuteron breakup on $^{24}$ Mg nucleus
A. Deltuva · D. Jurčiukonis
Deuteron breakup in collision with a $^{24} Mg$ nucleus is studied using rigorous three-body scattering equations, extended to include also the excitation of the nucleus. Predictions based on local and nonlocal nucleon-nucleus optical potentials with rotational quadrupole deformation enabling the excitation of the $^{24} Mg (2^{+})$ state are compared. The nonlocality effect is less pronounced than in the deuteron inelastic scattering $^{24} Mg (d, d^{'})$ at the same energies, and manifests itself quite differently for semi-inclusive differential cross sections of elastic and inelastic breakup.
nucl-thnucl-exPRC(2024)·1 citation
04
Berry Curvature and Spin-One Color Superconductivity
Noriyuki Sogabe🇺🇸 · Yi Yin🇨🇳
We explore the interplay between Berry curvature and topological properties in single-flavor color superconductors, where quarks form spin-one Cooper pairs. By deriving a new relation, we connect the topological nodal structure of the gap function in momentum space to the (nonabelian) Berry flux associated with paired quarks. This generalizes the early work by Li and Haldane [Phys. Rev. Lett. 120, 067003 (2018)] to systems with additional internal quantum numbers, such as color. In the ultrarelativistic limit, we uncover rich topological structures driven by the interplay of spin, chirality, and color. Specifically, we identify chirality-induced topological nodes in the transverse (opposite chirality pairing) polar and A phases. In contrast, the color-spin-locking phase lacks these nodes due to a nontrivial color Berry flux, which in turn induces gapless excitations with total Berry monopole charges of $\pm 3/2 -$ differing from conventional Weyl fermions. Our findings can be potentially extended to other fermionic systems carrying additional internal degrees of freedom.
nucl-thcond-mat.str-elcond-mat.supr-conhep-ph+1PRL(2025)·5 citations
05
Skyrme-Hartree-Fock-Bogoliubov mass models on a 3D mesh: IV. Improved description of the isospin dependence of pairing
Guilherme Grams · Nikolai N. Shchechilin · Adrian Sanchez-Fernandez · Wouter Ryssens · Nicolas Chamel · Stephane Goriely
Providing reliable data on the properties of atomic nuclei and infinite nuclear matter to astrophysical applications remains extremely challenging, especially when treating both properties coherently within the same framework. Methods based on energy density functionals (EDFs) enable manageable calculations of nuclear structure throughout the entire nuclear chart and of the properties of infinite nuclear matter across a wide range of densities and asymmetries. To address these challenges, we present BSkG4, the latest Brussels-Skyrme-on-a-Grid model. It is based on an EDF of the extended Skyrme type with terms that are both momentum and density-dependent, and refines the treatment of $^{1} S_{0}$ nucleon pairing gaps in asymmetric nuclear matter as inspired by more advanced many-body calculations. The newest model maintains the accuracy of earlier BSkGs for known atomic masses, radii and fission barriers with rms deviations of 0.633 MeV w.r.t. 2457 atomic masses, 0.0246 fm w.r.t. 810 charge radii, and 0.36 MeV w.r.t 45 primary fission barriers of actinides. It also improves some specific pairing-related properties, such as the $^{1} S_{0}$ pairing gaps in asymmetric nuclear matter, neutron separation energies, $Q_{β}$ values, and moments of inertia of finite nuclei. This improvement is particularly relevant for describing the $r$ -process nucleosynthesis as well as various astrophysical phenomena related to the rotational evolution of neutron stars, their oscillations, and their cooling.
nucl-thastro-ph.HEEPJA(2025)·14 citations
06
How neutron star properties disfavor a nuclear chiral density wave
Orestis Papadopoulos🇬🇧 · Andreas Schmitt🇬🇧
Cold and dense matter may break rotational symmetry spontaneously and thus form an anisotropic phase in the interior of neutron stars. We consider the concrete example of an anisotropic chiral condensate in the form of a chiral density wave. Employing a nucleon-meson model and taking into account fermionic vacuum fluctuations, we improve and extend previous results by imposing the conditions of electric charge neutrality and electroweak equilibrium, by allowing for a more general form of the vector meson self-interactions, and by including properties of pure neutron matter into the fit of the model parameters. We find that the conditions inside neutron stars postpone the onset of the chiral density wave to larger densities compared to isospin-symmetric nuclear matter. While this still allows for the construction of stars with an anisotropic core, we find that the chiral density wave is energetically preferred only in a corner of the parameter space where matter is too soft to generate stars with realistic masses. Therefore, taking into account constraints from astrophysical data, our calculation predicts an isotropic neutron star core.
nucl-thastro-ph.HEhep-phPRD(2025)·7 citations
07
Centrality definition in e+A collisions at the Electron-Ion Collider
Mariam Hegazy🇪🇬 · Aliaa Rafaat🇪🇬 · Niseem Magdy🇺🇸 · Wenliang Li🇺🇸 · Abhay Deshpande🇺🇸 · A. M. H. Abdelhady🇪🇬 · A.Y.Ellithi🇪🇬
In this work, we investigate the feasibility of defining centrality in electron-ion collisions at the Electron-Ion Collider (EIC) by examining the correlation between the impact parameter and several observables, including total energy, total transverse momentum, and total number of particles. Using the BeAGLE Monte Carlo generator, we simulate e+Au and e+Ru collisions at different energies and analyze the correlation between the impact parameter and these observables across different kinematic regions. Our findings indicate that the correlation is weak in the central rapidity region but becomes stronger in the forward and far-forward rapidity regions. However, the correlation is not sufficiently robust to allow for precise centrality determination. We conclude that defining centrality in electron-ion collisions is more challenging than in ion-ion collisions, necessitating further studies to develop a robust centrality definition for the EIC.
↳ hep-phnucl-thJ.Phys.G(2025)·0 citations
08
Schwinger-Keldysh effective action for hydrodynamics with approximate symmetries
Masaru Hongo🇯🇵 · Noriyuki Sogabe🇺🇸 · Mikhail A. Stephanov🇺🇸 · Ho-Ung Yee🇺🇸
We study the hydrodynamic theories with approximate symmetries in the recently developed effective action approach on the Schwinger-Keldysh (SK) contour. We employ the method of spurious symmetry transformation for small explicit symmetry-breaking parameters to systematically constrain symmetry-breaking effects in the non-equilibrium effective action for hydrodynamics. We apply our method to the hydrodynamic theory of chiral symmetry in Quantum Chromodynamics (QCD) at finite temperature and density and its explicit breaking by quark masses. We show that the spurious symmetry and the Kubo-Martin-Schwinger (KMS) relation dictate that the Ward-Takahashi identity for the axial symmetry, i.e., the partial conservation of axial vector current (PCAC) relation, contains a relaxational term proportional to the axial chemical potential, whose kinetic coefficient is at least of the second order in the quark mass. In the phase where the chiral symmetry is spontaneously broken, and the pseudo-Nambu-Goldstone pions appear as hydrodynamic variables, this relaxation effect is subleading compared to the conventional pion mass term in the PCAC relation, which is of the first order in the quark mass. On the other hand, in the chiral symmetry-restored phase, we show that our relaxation term, which is of the second order in the quark mass, becomes the leading contribution to the axial charge relaxation. Therefore, the leading axial charge relaxation mechanism is parametrically different in the quark mass across a chiral phase transition.
↳ hep-thcond-mat.stat-mechhep-phnucl-thPRD(2026)·15 citations

Affiliations

first authorsco-authorsvia INSPIRE