Nuclear Theory·nucl-th

Wednesday·February 26, 2025

17 papers—8 primary·9 cross-listed

01
Renormalization group analysis of electromagnetic properties of the deuteron
Thomas R. Richardson🇩🇪 · Immo C. Reis🇩🇪
The role of radiative corrections in low energy nuclear physics is beginning to receive more scrutiny. We examine the impact of these corrections for the deuteron charge form factor and the radiative capture process $n p \to d γ$ through the velocity renormalization group. In both cases, we find percent level shifts in the relevant observables after evolving the subtraction velocity to the typical velocity of nucleons in the bound state. This suggests that electromagnetic corrections constitute a non-negligible source of uncertainty in existing few-body calculations.
nucl-thhep-phPRC(2025)·3 citations
02
Neural network-based prediction of particle-induced fission cross sections for r-process nucleosynthesis trained with dynamical reaction models
J.L. Rodríguez-Sánchez · G. García-Jiménez · H. Alvarez-Pol · M. Feijoo-Fontán · A. Graña-González
Large-scale computations of fission properties play a crucial role in nuclear reaction network calculations simulating rapid neutron-capture process (r-process) nucleosynthesis. Due to the large number of fissioning nuclei contributing to the r-process, a description of particle-induced fission reactions is computationally challenging. In this work, we use theoretical calculations based on the INCL+ABLA models to train neural networks (NN). The results for the prediction of proton-induced spallation reactions, in particular fission, utilizing a large variety of NN models across the hyper-parameter space are presented, which are relevant for r-process calculations.
nucl-thNPA(2025)·0 citations
03
Dynamical evolution of critical fluctuations with second-order baryon diffusion coupled to chiral condensate
Azumi Sakai🇯🇵 · Koichi Murase🇯🇵 · Hirotsugu Fujii🇯🇵 · Tetsufumi Hirano🇯🇵
We develop a dynamical model to describe critical fluctuations in heavy-ion collisions, incorporating the baryon diffusion current and chiral condensate as dynamical degrees of freedom, to address their nontrivial scale separation. The model couples fluctuations of the chiral condensate $σ$ with baryon density fluctuations $n$ and the diffusion current $ν$ based on a second-order diffusion equation with a finite relaxation time of the baryon diffusion $τ_{R}$ . We analyze the spacetime evolution and these correlation functions of the fluctuations in one-dimensionally expanding background. We confirm that an appropriate relaxation time $τ_{R}$ ensures causality. We show that propagating waves with finite $τ_{R}$ split into two modes at the critical temperature due to a rapid change of kinetic coefficients. In the correlation functions, we find that dynamical $σ$ blurs the structure and peak around the critical temperature. With finite $τ_{R}$ , the effect of the critical fluctuations persists longer into the later stages of the evolution. These findings suggest importance of dynamical effects of the chiral condensate and baryon diffusion current in identifying critical-point signals in heavy-ion collisions, where the scale separation is nontrivial.
nucl-thhep-phPRC(2025)·1 citation
04
Hybrid stars with large quark cores within the parity doublet model and modified NJL model
Wen-Li Yuan🇨🇳 · Bikai Gao🇯🇵 · Yan Yan🇨🇳 · Renxin Xu🇨🇳
Using the parity doublet model (PDM) for hadronic matter and a modified Nambu-Jona-Lasinio (NJL) model for quark matter, we investigate the potential existence of two- and three-flavor quark matter in neutron star cores. Both models respect chiral symmetry, and a sharp first-order phase transition is implemented via Maxwell construction. We find stable neutron stars with quark cores within a specific parameter space that satisfies current astronomical observations. Typical neutron stars with masses around $1.4 M_{⊙}$ may possess deconfined quark matter in their centers. The hybrid star scenario with a two-flavor quark core offers enough parameter space to allow the neutron stars with large quark cores exceeding $\sim 1 M_{⊙}$ , and allow the early deconfinement position before $2 ρ_{0}$ , where $ρ_{0}$ is the nuclear saturation density. The observations of gravitational wave event GW170817 suggest a relatively large chiral invariant mass $m_{0} = 600 MeV$ in the PDM for scenarios involving three-flavor quark matter cores. The maximum mass of the hybrid star with a quark core is found to be approximately $2.2 M_{⊙}$ for both two- or three-flavor quark matter in their centers.
nucl-thastro-ph.HEPRD(2025)·18 citations
05
Stellar weak rates of the $r p$ -process waiting points: Effects of strong magnetic fields
Qi-Ye Hu · Long-Jun Wang · Yang Sun
Incorporating microscopic nuclear-structure information into the discussion of bulk properties of astronomical objects such as neutron stars has always been a challenging issue in interdisciplinary nuclear astrophysics. Using the $r p$ -process nucleosynthesis as an example, we studied the effective stellar $β^{+}$ and electron capture (EC) rates of eight waiting-point (WP) nuclei with realistic stellar conditions and presence of strong magnetic fields. The relevant nuclear transition strengths are provided by the projected shell model. We have found that, on average, due to the magnetic field effect, the $β^{+}$ and EC rates can increase by more than an order of magnitude for all combinations of density and temperature, as well as in each of WPs studied. We relate the onset field strength, at which the weak rates begin to increase, to nuclear structure quantities, $Q$ value or electronic chemical potential $μ_{e}$ . The enhanced weak rates may change considerably the lifetime of WPs, thereby modifying the current understanding of the $r p$ -process.
nucl-thastro-ph.GAPRL(2025)·5 citations
06
Microscopic study of halo nuclei through (p,t) reactions
Pierre Descouvemont
We analyze (p,t) two-neutron transfer reactions in a semi-microscopic model. The overlap integrals of the target nucleus are calculated in a microscopic cluster model. The Resonating Group Method (RGM) assumes a cluster structure of the nucleus, and is well adapted to halo nuclei since the long-range part of the wave function is accurately described. We focus on (p,t) reactions involving 6He and 11Li, which are well known core+n+n halo nuclei. The RGM is based on a nucleon-nucleon interaction, and therefore does not involve any fitting procedure. It also provides overlap integrals of excited states of the core nucleus. We present overlap integrals and spectroscopic factors of 6He and 11Li. We compute the 6He(p,t)alpha and 11Li(p,t)9Li cross sections at the DWBA, and compare them with experiments. For 11Li we also determine the 11Li(p,t)9Li* cross section which involves the first excited states of 9Li. A fair agreement with experiment is obtained, considering that no parameter is adjusted.
nucl-thPLB(2025)·1 citation
07
Microscopic investigation of $E 2$ matrix elements in atomic nuclei
S.P. Rouoof · Nazira Nazir · S. Jehangir · G.H. Bhat · J.A. Sheikh · N. Rather · S. Frauendorf
A systematic analysis of $E 2$ matrix elements of $^{72}$ Ge, $^{76}$ Ge, $^{168}$ Er, $^{186}$ Os, $^{188}$ Os, $^{190}$ Os, $^{192}$ Os and $^{194}$ Pt nuclides is performed using the beyond mean-field approach of triaxial projected shell model (TPSM). For these nuclei, large sets of $E 2$ matrix elements have been deduced from the multi-step Coulomb excitation experiments, and it is shown that TPSM approach provides a reasonable description of the measured transitions. We have evaluated 1496 $E 2$ matrix elements up to spin, $I = 10$ for the eight nuclei studied, and tabulate them for future experimental and theoretical comparisons. Further, shape invariant analysis has been performed with the calculated $E 2$ transitions using the Kumar-Cline sum rules. It is inferred from the analysis that the resulting shape, after configuration mixing of the quasiparticle states, transforms from $γ$ -rigid to that of $γ$ -soft for some nuclei, in conformity with the experimental data.
nucl-thnucl-exPRC(2025)·3 citations
08
Probing $Λ$ potential at high and low densities via $^3_{\Lambda}$H production in C+C reactions
Gao-Chan Yong🇨🇳 · J. L. Rodríguez-Sánchez🇪🇸 · Yapeng Zhang🇨🇳
The production of Lambda hyperons and light hypernuclei in heavy-ion collisions provides critical insights into the nuclear equation of state (EoS) and hyperon interactions in dense matter, addressing the longstanding ``hyperon puzzle'' in neutron star physics. Using the INCL+ABLA and AMPT-HC models, we systematically investigate C+C collisions at beam energies of 1.1 and 1.9 GeV/nucleon to explore the sensitivity of hyperon and hypernuclei yields to the EoS and hyperon potential. Our results reveal that Lambda hyperon production is predominantly influenced by the nuclear EoS, while light hypernuclei formation (e.g., $^3_{\Lambda}$H) exhibits stronger sensitivity to the hyperon potential at high/low densities with the incident beam energies of 1.1/1.9 GeV. The study provides a framework for future experiments at facilities like HIAF and FAIR/GSI to resolve the hyperon puzzle, thus advancing our understanding of quantum chromodynamics in high-density regimes.
nucl-thnucl-exPRC(2025)·3 citations
09
Determining the Density of the Sun with Neutrinos
Peter B. Denton🇺🇸 · Charles Gourley🇺🇸
The discovery of solar neutrinos confirmed that the inner workings of the Sun generally match our theoretical understanding of the fusion process. Solar neutrinos have also played a role in discovering that neutrinos have mass and that they oscillate. We combine the latest solar neutrino data along with other oscillation data from reactors to determine the Sun's density profile. We derive constraints given the current data and show the anticipated improvements with more reactor neutrino data from JUNO constraining the true oscillation parameters and more solar neutrino data from DUNE which should provide a crucial measurement of $h e p$ neutrinos.
↳ hep-phastro-ph.HEastro-ph.SRhep-ex+1PLB(2025)·6 citations
10
Maximal Magic for Two-qubit States
Qiaofeng Liu🇺🇸 · Ian Low🇺🇸 · Zhewei Yin🇺🇸
Magic is a quantum resource essential for universal quantum computation and represents the deviation of quantum states from those that can be simulated efficiently using classical algorithms. Using the Stabilizer Rényi Entropy (SRE), we investigate two-qubit states with maximal magic, which are most distinct from classical simulability, and provide strong numerical evidence that the maximal second order SRE is $ln (16/7) \approx 0.827$ , establishing a tighter bound than the prior $ln (5/2) \approx 0.916$ . We identify 480 states saturating the new bound, which turn out to be the fiducial states for the mutually unbiased bases (MUBs) generated by the orbits of the Weyl-Heisenberg (WH) group, and conjecture that WH-MUBs are the maximal magic states for $n$ -qubit, when $n \neq = 1$ and 3. We also reveal a striking interplay between magic and entanglement: the entanglement of maximal magic states is restricted to two possible values, $1/2$ and $1/ 2$ , as quantified by the concurrence; none is maximally entangled.
↳ quant-phcond-mat.stat-mechhep-phhep-th+1Quantum Sci.Technol.(2026)·33 citations
11
Emergent Hydrodynamic Mode on SU(2) Plaquette Chains and Quantum Simulation
Francesco Turro🇺🇸 · Xiaojun Yao🇺🇸
We search for emergent hydrodynamic modes in real-time Hamiltonian dynamics of $2 + 1$ -dimensional SU(2) lattice gauge theory on a quasi one dimensional plaquette chain, by numerically computing symmetric correlation functions of energy densities on lattice sizes of about $20$ with the local Hilbert space truncated at $j_{max} = \frac{1}{2}$ . Because of the Umklapp processes, we only find a mode for energy diffusion. The symmetric correlator exhibits transport peak near zero frequency with a width approximately proportional to momentum squared at small momentum, when the system is fully quantum ergodic, as indicated by the eigenenergy level statistics. This transport peak leads to a power-law $t^{- \frac{1}{2}}$ decay of the symmetric correlator at late time, also known as the long-time tail, as well as diffusion-like spreading in position space. We also introduce a quantum algorithm for computing the symmetric correlator on a quantum computer and find it gives results consistent with exact diagonalization when tested on the IBM emulator. Finally we discuss the future prospect of searching for the sound modes.
↳ hep-phcond-mat.stat-mechhep-latnucl-th+1PRD(2025)·17 citations
12
Real-time simulation of jet energy loss and entropy production in high-energy scattering with matter
João Barata🇨🇭 · Enrique Rico🇨🇭
In analogy to high-energy nuclear scattering experiments, we study a real-time scattering process between a propagating state and a dense target in $1 + 1$ -d massive QED. In our setup, we identify three distinct regimes that qualitatively characterize the evolution: for a dilute medium, the incoming probe state evolves nearly ballistically; in an intermediate setting, it traverses the matter, locally exciting it; and for dense targets, one approaches a black-disk limit, where the matter acts as a strong wall potential. We find evidence that the probe's energy loss rate scales linearly with the path length in the medium, and we study how the entanglement entropy reveals the mixing between the probe and medium states. With the goal of one day replicating high-energy nuclear experiments in quantum devices, we briefly discuss how the current tensor network-based simulations can be translated to a quantum simulator.
↳ hep-phnucl-thquant-phCommun.Phys.(2026)·26 citations
13
Five-body systems with Bethe-Salpeter equations
Gernot Eichmann🇦🇹 · M.T. Peña🇵🇹 · Raul D. Torres🇵🇹
We extend the Bethe-Salpeter formalism to systems made of five valence particles. Restricting ourselves to two-body interactions, we derive the subtraction terms necessary to prevent overcounting. We solve the five-body Bethe-Salpeter equation numerically for a system of five scalar particles interacting by a scalar exchange boson. To make the calculations tractable, we implement properties of the permutation group S5 and construct an approximation based on intermediate two- and three-body poles. We extract the five-body ground and excited states along with the spectra obtained from the two-, three-, and four-body equations. In the limit of a massless exchange particle, the two-, three, four- and five-body states coexist within a certain range of the coupling strength, whereas for heavier exchange particles the five-body system becomes Borromean. Our study serves as a building block for the calculation of pentaquark properties using functional methods.
↳ hep-phnucl-thPLB(2025)·8 citations
14
Rapidly spinning dark matter-admixed neutron stars
Lorenzo Cipriani🇮🇹 · Edoardo Giangrandi🇵🇹 · Violetta Sagun🇬🇧 · Daniela D. Doneva🇩🇪 · Stoytcho S. Yazadjiev🇧🇬
Millisecond pulsars, representing the older neutron star population, are believed to have undergone a prolonged period of dark matter accumulation, resulting in a higher dark matter content. Their extreme rotation makes them unique laboratories for studying rapidly rotating neutron stars admixed with dark matter. In this work, we model uniformly rotating neutron stars with a dark matter component that rotates independently from the baryon matter, allowing for the investigation of both co-rotating and counter-rotating scenarios. We examine the impact of dark matter rotation on the macroscopic properties of neutron stars, including the mass-radius relation, the mass-shedding Keplerian limit, and moments of inertia, for various dark matter particle masses and total fractions, considering both core and halo distributions. Our findings provide a more comprehensive understanding of how dark matter influences the equilibrium properties of rotating neutron stars, offering new insights into the astrophysical implications of self-interacting dark matter.
↳ astro-ph.HEgr-qchep-phnucl-thPRD(2025)·16 citations
15
Two- and three-meson scattering amplitudes with physical quark masses from lattice QCD
Sebastian M. Dawid🇺🇸 · Zachary T. Draper🇺🇸 · Andrew D. Hanlon🇺🇸 · Ben Hörz🇩🇪 · Colin Morningstar🇺🇸 · Fernando Romero-López🇨🇭 · Stephen R. Sharpe🇺🇸 · Sarah Skinner🇺🇸
We study systems of two and three mesons composed of pions and kaons at maximal isospin using four CLS ensembles with $a \approx 0.063$ fm, including one with approximately physical quark masses. Using the stochastic Laplacian-Heaviside method, we determine the energy spectrum of these systems including many levels in different momentum frames and irreducible representations. Using the relativistic two- and three-body finite-volume formalism, we constrain the two and three-meson K matrices, including not only the leading $s$ wave, but also $p$ and $d$ waves. By solving the three-body integral equations, we determine, for the first time, the physical-point scattering amplitudes for $3 π^{+}$ , $3 K^{+}$ , $π^{+} π^{+} K^{+}$ and $K^{+} K^{+} π^{+}$ systems. These are determined for total angular momentum $J^{P} = 0^{-}$ , $1^{+}$ , and $2^{-}$ . We also obtain accurate results for $2 π^{+}$ , $π^{+} K^{+}$ , and $2 K^{+}$ phase shifts. We compare our results to Chiral Perturbation Theory, and to phenomenological fits.
↳ hep-lathep-phnucl-thPRD(2025)·29 citations
16
On the momentum space structure of the quark propagator
O. Oliveira🇵🇹 · T. Frederico🇧🇷 · W. de Paula🇧🇷
The structure of the quark propagator in momentum space is explored taking into account non-perturbative QCD dynamics constraints for the quark spectral densities derived previously. We assume that the scalar and vector component of the quark propagator share a simple pole but not its residuum, together with other structures. Furthermore, a connection between the poles of the quark propagator and the zeros of the quark wave function $Z (p^{2})$ is established. Asymptotic scaling laws for the representation of the quark propagator, after removing the shared pole, are also derived. The confrontation of our results with lattice data for the full QCD quark propagator data are in good agreement. Exploring the link with the lattice data and looking at the Bethe-Salpeter vertex and amplitude, in the chiral limit, we are able to provide estimations for these quantities, for $f_{π}$ and for the shared pole mass. The pole mass reproduces the constituent quark mass used in the quark models.
↳ hep-phhep-thnucl-thEPJC(2025)·3 citations
17
Rotational stability of magnetic field in rotating quark-gluon plasma
Aritra Das🇺🇸 · Kirill Tuchin🇺🇸
Relaxation of the magnetic field in rigidly rotating quark-gluon plasma is studied. It is shown that the infrared modes satisfying $k < ∣ m ∣Ω$ and $k < ∣ m \pm 1∣Ω$ , where integer $m$ is the projection of the orbital angular momentum along the rotating axis and $Ω$ is the angular velocity, are unstable. The instability onset time and the magnetic field growth rate are computed for a standard initial profile of the magnetic field. Given the present phenomenological values of $Ω$ and electrical conductivity $σ$ the instability is not expected to be a significant factor in the field's time evolution.
↳ hep-phnucl-thNPA(2025)·6 citations

Affiliations

first authorsco-authorsvia INSPIRE