Nuclear Theory·nucl-th

Tuesday·August 5, 2025

13 papers—7 primary·6 cross-listed

08
Re-optimization of a deep neural network model for electron-carbon scattering using new experimental data
Beata E. Kowal🇵🇱 · Krzysztof M. Graczyk🇵🇱 · Artur M. Ankowski🇵🇱 · Rwik Dharmapal Banerjee🇵🇱 · Jose L. Bonilla🇵🇱 · Hemant Prasad🇵🇱 · Jan T. Sobczyk🇵🇱
We present an updated deep neural network model for inclusive electron-carbon scattering. Using the bootstrap model [Phys.Rev.C 110 (2024) 2, 025501] as a prior, we incorporate recent experimental data, as well as older measurements in the deep inelastic scattering region, to derive a re-optimized posterior model. We examine the impact of these new inputs on model predictions and associated uncertainties. Finally, we evaluate the resulting cross-section predictions in the kinematic range relevant to the Hyper-Kamiokande and DUNE experiments.
↳ hep-phcs.LGnucl-exnucl-thPRC(2025)·0 citations
09
Lattice Calculation of Short-Range Contributions to Neutrinoless Double-Beta Decay $π^{-} \to π^{+} ee$ at Physical Pion Mass
Peter Boyle🇺🇸 · Felix Erben🇨🇭 · Xu Feng🇨🇳 · Jonathan M. Flynn🇬🇧 · Nicolas Garron🇬🇧 · Taku Izubuchi🇺🇸 · Luchang Jin🇺🇸 · Rajnandini Mukherjee🇬🇧 · J. Tobias Tsang🇨🇭 · Xin-Yu Tuo🇺🇸
Neutrinoless double-beta ( $0 ν β β$ ) decays provide an excellent probe for determining whether neutrinos are Dirac or Majorana fermions. The short-range matrix elements associated with the $π^{-} \to π^{+} ee$ process contribute at leading order in the $0 ν β β$ decay channel $nn \to pp ee$ through pion exchange between nucleons. However, current lattice calculations show notable discrepancies in predicting these short-range contributions. To address this issue, we perform a lattice QCD calculation of the $π^{-} \to π^{+} ee$ matrix elements using domain wall fermion ensembles at the physical pion mass generated by the RBC and UKQCD Collaborations. To mitigate contamination from around-the-world effects, we develop a new method to reconstruct and subtract them directly from lattice data. We then perform a nonperturbative renormalization using the RI/SMOM scheme. Compared with previous studies, this work reduces the uncertainties in the matrix elements and provides an independent cross-check that helps to reconcile the discrepancies among previous lattice calculations.
↳ hep-lathep-phnucl-thPRD(2026)·1 citation
10
$ν p$ -process in Core-Collapse Supernovae: Imprints of General Relativistic Effects
Alexander Friedland · Derek J. Li · Giuseppe Lucente · Ian Padilla-Gay · Amol V. Patwardhan
The origin of a number of proton-rich isotopes in the solar system has been a long-standing puzzle. A promising explanation is the $ν p$ -process, which is posited to operate in the neutrino-driven outflows that form inside core-collapse supernovae after shock revival. While recent studies have analyzed several relevant physical effects that influence the efficiency of this process, the impact of General Relativity (GR) on it remains unexplored. We perform a comparative analysis of the time-integrated $ν p$ -process yields in Newtonian and fully GR calculations, using detailed models of time-evolving outflow profiles. The GR effects are seen to suppress the production of seed nuclei, significantly boosting the resulting $p$ -nuclide abundances. Our reference GR model, with an 18~ $M_{⊙}$ progenitor, reproduces both the relative and absolute solar system abundances of the entire set of the $p$ nuclides in the mass range $74 \leq A \leq 102$ . The yields are suboptimal in our 12.75~ $M_{⊙}$ GR model, where the outflow transitions to the supersonic regime several seconds into the explosion, suppressing further $p$ -nuclide production. In both models, most of the production of the crucial $^{92, 94} Mo$ and $^{96, 98} Ru$ $p$ isotopes occurs relatively early, 1--3 seconds after shock revival. In contrast, a large fraction of the shielded isotope $^{92} Nb$ is produced in the subsequent ejecta. The impact of GR on this isotope is especially large, with its final abundance boosted by a factor of 25 compared to a Newtonian calculation. In summary, with the GR effects taken into account, the $ν p$ -process in a sufficiently massive progenitor can provide a unifying explanation for the origin of all $p$ nuclei in the solar system up to $^{102}$ Pd.
↳ astro-ph.HEhep-phnucl-thJCAP(2026)·3 citations
11
Gravitational form factors of the nucleon from the chiral effective model
Daisuke Fujii · Mamiya Kawaguchi · Mitsuru Tanaka
We investigate the confining pressure and associated global property, i.e, D-term, of the nucleon using the skyrmion approach formulated within scale-invariant chiral perturbation theory. In this framework, the nucleon is modeled as a skyrmion, and a scalar meson is introduced to incorporate the effects of the scale anomaly via low-energy theorems. The contributions from the current quark mass and gluonic dynamics to the scale anomaly are encoded through the pion and scalar meson masses, respectively. By decomposing the nucleon's energy-momentum tensor, we isolate the anomalous components and analyze their role in generating pressure. We find that the gluonic contribution to the scale anomaly plays a dominant role in producing confining pressure. In comparison with results from conventional chiral perturbation theory in the chiral limit, the total pressure derived from sChPT provides improved qualitative agreement with lattice QCD results. We also evaluate the D-term and compare it with recent lattice and model-independent determinations.
↳ hep-phhep-thnucl-thPoS(2026)·0 citations
12
Nuclear modification factor $I_{AA}$ in $AA$ collisions at RHIC and LHC energies in scenarios with and without quark-gluon plasma formation in $pp$ collisions
B.G. Zakharov🇷🇺
We calculate the away-side hadron-triggered modification factor $I_{AA}$ in $AA$ collisions at RHIC and LHC energies for scenarios with and without quark-gluon plasma formation in $pp$ collision. We find that for both scenarios theoretical results for $I_{AA}$ agree well with the available data for 2.76 TeV Pb+Pb and 0.2 TeV Au+Au collisions. We make predictions for $I_{AA}$ in 7 TeV O+O collisions that are planned at the LHC. Our results show that measuring $I_{O O}$ in the whole centrality interval and at small centrality ( $≲ 5$ %) may give information on the presence of jet quenching in $pp$ collisions.
↳ hep-phnucl-thJETP Lett.(2025)·0 citations
13
PSR J0614-3329: A NICER case for Strange Quark Stars
Swarnim Shirke🇮🇳 · Rajesh Maiti🇮🇳 · Debarati Chatterjee🇮🇳
Precise measurements of neutron star masses and radii by the NICER mission impose important constraints on the nuclear equation of state. The most recent NICER measurement of PSR J0614-3329 reported an equatorial radius of $R_{e q} = 10.2 9_{- 0.86}^{+ 1.01}$ km for a mass of $M = 1.4 4_{- 0.07}^{+ 0.06} M_{⊙}$ . Considering all the NICER measurements to date, we find substantial evidence using Bayesian hypothesis ranking for strange quark stars over physically motivated models of neutron stars compatible with this low radius. This provides a strong case for quark matter in neutron stars and also for the possible existence of strange quark stars, a consequence of the Bodmer-Witten hypothesis, suggesting that they could be considered among the population of compact stars during analyses of astrophysical data. Using a wide sample of equations of state, we report the nucleonic equations of state that best fit current observations and rule out one model of strange quark matter.
↳ astro-ph.HEastro-ph.SRhep-phnucl-th11 citations

Affiliations

first authorsco-authorsvia INSPIRE

Re-optimization of a deep neural network model for electron-carbon scattering using new experimental data

Lattice Calculation of Short-Range Contributions to Neutrinoless Double-Beta Decay π−→π+ee at Physical Pion Mass

νp-process in Core-Collapse Supernovae: Imprints of General Relativistic Effects

Gravitational form factors of the nucleon from the chiral effective model

Nuclear modification factor IAA​ in AA collisions at RHIC and LHC energies in scenarios with and without quark-gluon plasma formation in pp collisions

PSR J0614-3329: A NICER case for Strange Quark Stars

Affiliations

Lattice Calculation of Short-Range Contributions to Neutrinoless Double-Beta Decay $π^{-} \to π^{+} ee$ at Physical Pion Mass

$ν p$ -process in Core-Collapse Supernovae: Imprints of General Relativistic Effects

Nuclear modification factor $I_{AA}$ in $AA$ collisions at RHIC and LHC energies in scenarios with and without quark-gluon plasma formation in $pp$ collisions