Nuclear Theory·nucl-th

Wednesday·July 9, 2025

8 papers—5 primary·3 cross-listed

01
An intrinsic-state formalism for the Interacting Boson-Fermion Model with configuration mixing
E. Maya-Barbecho · J.E. García-Ramos
In this letter, we present the intrinsic state formalism of the Interacting Boson-Fermion Model incorporating both 0p-0h and 2p-2h (regular and intruder) configurations. The framework allows to deal with the unpaired fermion in either a single-j or multi-j orbital and is applicable to both axial and triaxial nuclear shapes. The formalism is applied to a schematic transitional region where regular and intruder configurations coexist and cross. We show that the boson-fermion part of the Hamiltonian can either enhance or suppress the emergence of a type II Quantum Phase Transition.
nucl-thnucl-exPLB(2025)·3 citations
02
Dynamical scheme for computing the mass parameter of a system in a medium
Agata Zdanowicz · Daniel Pęcak · Piotr Magierski · Gabriel Wlazłowski
We present a new method for extracting a mass parameter using time-dependent density functional theory for an arbitrary physical system, provided the adiabatic limit is achievable. This approach works for collective variables also in the presence of a medium, in particular for the nuclei interacting with a neutron background. We apply the method to extract mass parameters of impurities in the neutron star crust, like their inertial masses and quadrupole mass parameters. The extracted mass parameters at various depths of the inner crust are compared with other methods, including the hydrodynamic approach. The presented method opens avenues for the construction of an effective model of neutron star crust grounded in microscopic calculations.
nucl-thastro-ph.HEcond-mat.supr-conPRC(2025)·1 citation
03
Neural Unfolding of the Chiral Magnetic Effect in Heavy-Ion Collisions
Shuang Guo🇨🇳 · Lingxiao Wang🇯🇵 · Kai Zhou🇨🇳 · Guo-Liang Ma🇨🇳
The search for the chiral magnetic effect (CME) in relativistic heavy-ion collisions (HICs) is challenged by significant background contamination. We present a novel deep learning approach based on a U-Net architecture to time-reversely unfold the dynamics of CME-related charge separation, enabling the reconstruction of the physics signal across the entire evolution of HICs. Trained on the events simulated by a multi-phase transport model with different cases of CME settings, our model learns to recover the charge separation based on final-state transverse momentum distributions at either the quark-gloun plasma freeze-out or hadronic freeze-out. This devises a methodological tool for the study of CME and underscores the promise of deep learning approaches in retrieving physics signals in HICs.
nucl-thhep-phnucl-exChin.Phys.Lett.(2025)·4 citations
04
Revisiting $η^{'} (958)$ nuclear states
E. Friedman🇮🇱 · A. Gal🇮🇱
Observing $η^{'}$ -nuclear quasibound states requires that the $η^{'}$ -nuclear potential is both sufficiently attractive and weakly absorptive, as confirmed by the CBELSA/TAPS collaboration analysis of inclusive $η^{'}$ production experiments on nuclear targets, including liquid hydrogen (LH $_{2}$ ). Here we present an alternative derivation of the $η^{'}$ -nuclear potential, constrained by near-threshold $pp \to pp η^{'}$ and $γ p \to η^{'} p$ production experiments on a free proton. The resulting $η^{'}$ -nuclear potential is weakly attractive and strongly absorptive, to the extent that observation of clear signals of $η^{'}$ -nuclear quasibound states is unlikely. Possible exceptions resulting from the dynamics of the nearby $I = \frac{1}{2}$ $J = (\frac{1}{2})^{-}$ nucleon resonance $N^{*}$ (1895) are briefly discussed.
nucl-thhep-phnucl-exPLB(2025)·3 citations
05
Glauber predictions for oxygen and neon collisions at energies available at the LHC
Constantin Loizides🇨🇭
The Glauber model is a widely used framework for describing the initial conditions in high-energy nuclear collisions. TGlauberMC is a Monte Carlo implementation of this model that enables detailed, event-by-event calculations across various collision systems. In this work, I present an updated version of TGlauberMC (3.3), which incorporates recent theoretical developments and improved parameterizations, especially relevant for small collision systems. I focus on the oxygen-oxygen (OO), neon-neon (NeNe), and proton-oxygen (pO) collisions at the Large Hadron Collider (LHC) in July 2025, where precise modelling of nuclear geometry and fluctuations is essential. The updated version includes revised nuclear density profiles and an enhanced treatment of nucleon substructure. Geometrical cross sections for all relevant collision systems are calculated and initial-state observables are explored to provide predictions for particle production trends at $s_{nn}$ =5.36 TeV. In particular, a prediction for the centrality dependence of mid-rapidity multiplicity in OO and NeNe collisions is obtained. The updated code is publicly available to support the heavy-ion community with a robust and flexible tool for studying strongly interacting matter in small and intermediate-sized nuclear systems.
nucl-thhep-exhep-phnucl-exPRC(2026)·38 citations
06
Thermal relaxation and the complete set of second order transport coefficients for the unitary Fermi gas from kinetic theory
Christian Hall · Thomas Schaefer
We compute the complete set of second order transport coefficients of the unitary Fermi gas, a dilute gas of spin 1/2 particles interacting via an $s$ -wave interaction tuned to infinite scattering length. The calculation is based on kinetic theory and the Chapman-Enskog method at second order in the Knudsen expansion. We take into account the exact two-body collision integral. We extend previous results on second order coefficients related to shear stress by including terms related to heat flow and gradients of the fugacity. We confirm that the thermal relaxation time is given by the simple estimate $τ_{κ} = κm / (c_{P} T)$ even if the full collision kernel is taken into account. Here, $κ$ is the thermal conductivity, $m$ is the mass of the particles, $c_{P}$ is the specific heat at constant pressure, and $T$ is the temperature.
↳ cond-mat.quant-gasnucl-thPRA(2025)·0 citations
07
Gravitational form factors of pions, kaons and nucleons from dispersion relations
Xiong-Hui Cao🇨🇳 · Feng-Kun Guo🇨🇳 · Qu-Zhi Li🇨🇳 · Bo-Wen Wu🇨🇳 · De-Liang Yao🇨🇳
The gravitational form factors of pions, kaons and the nucleons are investigated by employing modern dispersive techniques and chiral perturbation theory. We determine the gravitational form factors of pions and kaons, extending our analysis to explore the pion mass dependence of these form factors at several unphysical pion masses up to 391 MeV, for which lattice results exist for the meson-meson scattering phase shifts. We also review our analysis on the nucleon gravitational form factors at the physical pion mass, and then systematically calculate various three-dimensional spatial and two-dimensional transverse density distributions for the nucleons. These results provide new insights into the mass distribution inside nucleons. As a by-product, we match our dispersion relation results and those obtained from chiral perturbation theory with external gravitational source at the next-to-next-to-leading order, yielding values for the low-energy constants $c_{8} = - 4.2 8_{- 0.38}^{+ 0.37} GeV^{- 1}$ and $c_{9} = - 0.6 8_{- 0.05}^{+ 0.06} GeV^{- 1}$ . These results offer a robust benchmark for future experimental and theoretical studies.
↳ hep-phhep-exhep-latnucl-thEur.Phys.J.ST(2026)·25 citations
08
The nuclear charge radius of $^{13} C$
Patrick Müller · Matthias Heinz · Phillip Imgram · Kristian König · Bernhard Maass · Takayuki Miyagi · Wilfried Nörtershäuser · Robert Roth · Achim Schwenk
The size is a key property of a nucleus. Accurate nuclear radii are extracted from elastic electron scattering, laser spectroscopy, and muonic atom spectroscopy. The results are not always compatible, as the proton-radius puzzle has shown most dramatically. Beyond helium, precision data from muonic and electronic sources are scarce in the light-mass region. The stable isotopes of carbon are an exception. We present a laser spectroscopic measurement of the root-mean-square (rms) charge radius of $^{13} C$ and compare this with ab initio nuclear structure calculations. Measuring all hyperfine components of the $2^{3} S \to 2^{3} P$ fine-structure triplet in $^{13} C^{4 +}$ ions referenced to a frequency comb allows us to determine its center-of-gravity with accuracy better than $2 MHz$ although second-order hyperfine-structure effects shift individual lines by several $GHz$ . We improved the uncertainty of $R_{c} (^{13} C)$ determined with electrons by a factor of $6$ and found a $3 σ$ discrepancy with the muonic atom result of similar accuracy.
↳ physics.atom-phnucl-thNature Commun.(2025)·8 citations

Affiliations

first authorsco-authorsvia INSPIRE