Nuclear Theory·nucl-th

Monday·June 2, 2025

8 papers—5 primary·3 cross-listed

01
AI-Assisted analysis of $^{28}$ Si $^{*}$ $\to$ 7 $α$ break-up data
Theodoros Depastas🇺🇸 · Aldo Bonasera🇺🇸 · Joe Natowitz🇺🇸
Mid-weight $α$ -conjugate nuclei are predicted to possess exotic toroid-like resonances with high angular momenta. The search for these states in $^{28}$ Si $^{*}$ is the main point of two published experimental investigations of the peripheral $^{28}$ Si + $^{12}$ C reaction by Cao and collaborators and by Hannaman and collaborators. In this work, we develop a novel Artificial Intelligence (AI)-based machine learning method utilizing the Gaussian Mixture Model (GMM) to analyze available experimental and theoretical data. We additionally study the reaction with the Hybrid $α$ -Cluster (H $α$ C) model. In all the examined data our results suggest the presence of underlying structure which is close to that predicted for toroidal states.
nucl-thPRC(2025)·3 citations
02
Radial and Non-Radial Oscillations of Protoneutron Stars with Hyperonic Composition
Prashant Thakur🇮🇳 · Adamu Issifu🇧🇷 · Ishfaq Ahmad Rather🇩🇪 · Y. Lim🇰🇷 · Tobias Frederico🇧🇷
This paper explores radial and non-radial oscillations of protoneutron stars (PNSs) as they evolve from hot, neutrino-rich configurations through deleptonization to cold, catalyzed states. The equation of state (EoS) is modeled using a density-dependent relativistic mean-field framework, with stellar evolution characterized by changes in entropy and lepton fraction. Both nucleonic and hyperonic compositions are considered. Non-radial $f$ - and $p_{1}$ -mode oscillations are computed using both the Cowling approximation and the full General Relativistic framework. Trapped neutrinos initially increase the error in the Cowling approximation for $f$ -modes, which decreases during deleptonization and rises again in the cold phase. In contrast, $p_{1}$ -mode errors peak during intermediate stages due to evolving pressure and density gradients. The emergence of hyperons modestly raises oscillation frequencies in both modes. Existing universal relations for $f$ -mode frequency and damping time lack model independence for PNSs, motivating a more robust relation. In particular, our proposed universal relation involving the moment of inertia and $η ~$ shows strong agreement across all evolutionary phases, offering a temperature-sensitive, model-independent scaling for asteroseismology. Radial oscillations of a $1.4 M_{⊙}$ PNS are also studied for different EoSs. Our results show that displacement ( $ξ$ ) and pressure perturbation ( $η$ ) profiles are highly sensitive to thermal state, composition, and compactness. Hyperonic stars show higher frequencies, altered node structures, and stronger pressure perturbations due to EoS softening. Differences in frequency separation $Δ ν_{n}$ and fundamental frequency $ν_{0}$ between nucleonic and hyperonic models provide clear observational diagnostics for probing the interiors of PNSs and constraining the EoS of dense matter.
nucl-thastro-ph.HEEPJC(2026)·6 citations
03
Next-to-leading-order prediction for the neutrinoless double-beta decay
Y. L. Yang🇨🇳 · P. W. Zhao🇨🇳
The neutrinoless double-beta decay ( $0 ν β β$ ) of two neutrons $nn \to pp ee$ is the elementary subprocess of $0 ν β β$ decay in nuclei. Accurate knowledge of the $nn \to pp ee$ amplitude is required to pin down the short-range contributions in the nuclear matrix elements of the candidate nuclei for large-scale $0 ν β β$ searches. In this Letter, we report the first next-to-leading-order prediction of the nn \rightarrow ppee amplitude, with Bayesian uncertainty quantification. This is made possible by the development of the relativistic chiral effective field theory, in which no unknown contact term is required up to next-to-leading order. The theory is validated by reproducing in a parameter-free way the available data on the charge independence and charge symmetry breaking contributions in the two-nucleon scattering. The present work makes an essential step towards addressing the uncertainty in the theoretical calculations of the nuclear matrix elements relevant for $0 ν β β$ searches.
nucl-thhep-exhep-phnucl-exPRL(2025)·4 citations
04
Neutrino emission from neutron star matter
Omar Benhar🇮🇹 · Lucas Tonetto🇮🇹
The temperature of a newly formed neutron star is believed to be as high as $1 0^{11}$ ~K, corresponding to a thermal energy of about $10$ MeV. After a time $t \sim 50 s$ , the neutrino mean free path in nuclear matter exceeds the typical star radius, R~ $\sim$ ~10 Km, and neutrino emission becomes the dominant mechanism of energy loss, eventually bringing the temperature down to $\sim 1 0^{8}$ ~K. Neutrinos also play a critical role in determining the composition of matter in the star interior, consisting primarily of a charge-neutral mixture of neutrons, protons and leptons in $β$ -equilibrium. This article provides an introduction to the weak interactions of nucleons in nuclear matter, as well as a concise review of the neutrino emission reactions taking place in the neutron star core. The approximations involved in the standard theoretical treatment of thermal and dynamical effects are analysed in the light of the recent progress of the field, and the prospects for future developments are outlined.
nucl-thIJMPE(2025)·2 citations
05
Heavy Ion Double Charge Exchange Reactions as Probes for Two-Body Transition Densities
Jessica I.Bellone · Maria Colonna · Danilo Gambacurta · Horst Lenske
Collisional heavy ion double charge exchange (DCE) reactions, induced by second order nucleon-nucleon interactions, are shown to provide access to the two-body transition densities of the complementary DCE transitions in the interacting nuclei. Corresponding two-body operators are introduced, treating the second order distorted wave reaction amplitude in the s-channel interaction form. The theoretical results are applied to the reaction $^{18} O +^{76} S e \to^{18} N e +^{76} G e$ at $T_{l ab} = 270$ ~MeV, being $^{76} G e$ a candidate for neutrino--less double beta decay.
nucl-thPRC(2025)·5 citations
06
Factorized QED and QCD Contribution to Deeply Inelastic Scattering
Justin Cammarota🇺🇸 · Jian-Wei Qiu🇺🇸 · Kazuhiro Watanabe🇯🇵 · Jia-Yue Zhang🇺🇸
We present the first calculation of next-to-leading order (NLO) factorized QED and QCD contributions to the short-distance hard coefficients of inclusive lepton-hadron deep inelastic scattering (DIS) in a joint QED and QCD factorization approach. Unlike the traditional radiative correction approach to handle the collision-induced QED contributions to DIS, QED radiation from all charged leptons and quarks are treated equally, and their collinear sensitivities are systematically factorized into corresponding universal lepton and parton distribution functions. We demonstrate that the NLO factorized QED contribution is completely infrared safe and calculable without the need of any parameters other than the standard factorization scale in the same way as the factorized QCD contribution. We discuss the potential impact of this joint factorization approach on the extraction of partonic information from lepton-hadron DIS.
↳ hep-phhep-exnucl-exnucl-thPRD(2025)·10 citations
07
Electroexcitation of Nucleon Resonances and the Emergence of Hadron Mass
Patrick Achenbach🇺🇸 · Daniel S. Carman🇺🇸 · Ralf W. Gothe🇺🇸 · Kyungseon Joo🇺🇸 · Victor I. Mokeev🇺🇸 · Craig D. Roberts🇨🇳
Developing an understanding of phenomena driven by the emergence of hadron mass (EHM) is one of the most challenging problems in the Standard Model. This discussion focuses on the impact of results on nucleon resonance ( $N^{*}$ ) electroexcitation amplitudes (or $γ_{v} p N^{*}$ electrocouplings) obtained from experiments during the 6-GeV era in Hall~B at Jefferson Lab on understanding EHM. Analyzed using continuum Schwinger function methods (CSMs), these results have revealed new pathways for the elucidation of EHM. A good description of the $Δ (1232) 3/ 2^{+}$ , $N (1440) 1/ 2^{+}$ , and $Δ (1600) 3/ 2^{+}$ electrocouplings, achieved by CSM analyses that express a realistic dressed quark mass function, sheds light on the strong interaction dynamics that underlies EHM. Extensions to nucleon resonance studies for higher-mass states are outlined, as well as experimental results anticipated in the 12-GeV era at Jefferson Lab and those that would be enabled by a further increase of the beam energy to 22~GeV.
↳ hep-phnucl-exnucl-thSymmetry(2025)·23 citations
08
Review on recent progress in the study of the $N^{*} (920)$ subthreshold singularity and the $σ / f_{0} (500)$ meson
Qu-Zhi Li🇨🇳 · Zhiguang Xiao🇨🇳 · Han-Qing Zheng🇨🇳
We summarize recent results on studies of $π π$ and $π N$ scatterings. They include the finding of a negative-parity nucleon pole with a mass lower than the nucleon mass, and the pole trajectory of $f_{0} (500)$ as the pion mass varies. The results are obtained from model-independent dispersion analyses. We also study the thermal properties of $f_{0} (500)$ based on the $O (N)$ $σ$ model and $N / D$ method.
↳ hep-phhep-latnucl-thEur.Phys.J.ST(2026)·5 citations

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first authorsco-authorsvia INSPIRE