Nuclear Theory·nucl-th

Tuesday·February 10, 2026

14 papers—5 primary·9 cross-listed

01
Correlations of Feed-down Hadrons in a Thermal Model
Claude Pruneau🇺🇸 · Victor Gonzalez🇺🇸 · Oveis Sheibani🇺🇸 · Chun Shen🇺🇸 · Yash Patley🇮🇳 · Basanta Nandi🇮🇳 · Ana Marin🇩🇪
We examine the potential impact of strong decays on the magnitude of fluctuations of net quantum numbers and integrals of balance functions based on a thermal hadron gas model. The calculations are based on a comprehensive list of known hadrons with masses up to 2.5 GeV/ $c^{2}$ and include all decays of these hadrons with known branching fractions. The calculations are performed at vanishing baryo-chemical potential for temperatures between 140 and 200 MeV. We show that the decays feed-down substantially impact the single yield of measurable ``stable particles" as well as those of correlated densities of these species. Decays can then potentially have large and non-trivial impacts on measurements of net quantum number cumulants and balance functions. These observations are particularly important in the context of the search for the QCD critical point at the RHIC Beam Energy Scan as well as efforts to determine chemical susceptibilities near the phase transition at RHIC or LHC energies. Results obtained in this work also shed light on the importance of feed-down in measurements of balance functions in elementary p-p and nucleus-nucleus collisions.
nucl-thhep-phnucl-exPRC(2026)·0 citations
02
Comprehensive table of calculated Huff factors
Yuichi Uesaka · Tomoya Naito · Shuichiro Ebata · Megumi Niikura
We present a systematic calculation of the Huff factor for nuclei with atomic numbers ( $Z$ ) in the range of $6 \leq Z \leq 94$ . The Huff factor quantifies the increase in the partial lifetime of the decay-in-orbit (DIO) of the muonic atom and serves as an essential correction factor for extracting the nuclear muon capture rate from the measured lifetimes of the muonic atom. However, previous calculations typically provided only the atomic number dependence and neglected isotope dependence -- an assumption whose reliability had not been examined, despite its importance for a comprehensive understanding of the nuclear muon capture rate. In this work, we calculate the Huff factor using nuclear charge distributions obtained from a fully self-consistent microscopic nuclear structure model that incorporates pairing and deformation effects. The resultant Huff factors exhibit a monotonic decrease with increasing $Z$ , while the isotope dependence is found to be small. Our results also show good agreement with previous calculations, supporting the reliability of the present framework. The comprehensive set of Huff factors presented here constitutes the first unified values currently available and will serve as a basis for future evaluations of muon nuclear data.
nucl-thhep-phnucl-exAtom.Data Nucl.Data Tabl.(2026)·1 citation
03
New solution to the hyperon puzzle of neutron stars: Quantum many-body effects
Hao-Fu Zhu🇨🇳 · Guo-Zhu Liu🇨🇳 · Xufen Wu🇨🇳 · Ye-Fei Yuan🇨🇳
The hyperon puzzle refers to the challenge of reconciling the existence of hyperons in neutron star cores and the observed high masses of neutron stars. The recent discovery of PSR J0952-0607 ( $2.35 \pm 0.17 M_{⊙}$ ) has intensified this challenge. Existing solutions fail to achieve such a high mass, and often predict unrealistically fast cooling that is at odds with observations. Here, we propose a novel solution to the hyperon puzzle. Using the Dyson-Schwinger equation approach, we incorporate the quantum many-body effects caused by strong baryon-meson interactions into the equation of state for cold baryonic matter and find it stiff enough to support a maximum hyperon-star mass of $M_{max} \approx 2.59 M_{⊙}$ , which can explain all the observed high neutron-star masses. The resulting proton and hyperon fractions are remarkably low, thus the nucleonic and hyperonic direct Urca processes are significantly suppressed. As a result, fast cooling typically does not occur in ordinary neutron stars.
nucl-thastro-ph.HEcond-mat.str-elPRD(2026)·2 citations
04
Stochastic many-body perturbation theory for high-order calculations
Xin Zhen · Rongzhe Hu · Junchen Pei · Furong Xu
High-order perturbative $ab initio$ calculations are challenging due to the rapidly growing configuration space and the difficulty of assessing convergence. In this letter, we introduce perturbation theory quantum Monte Carlo (PTQMC), a stochastic approach designed to compute high-order many-body perturbative corrections. By representing the perturbative wave function with random walkers in configuration space, PTQMC avoids the exponential scaling inherent to conventional constructions of high-rank excitation operators. Benchmark calculations for the Richardson pairing model demonstrate that PTQMC accurately reproduces exact many-body perturbation theory (MBPT) coefficients up to 16th order, even in strongly divergent regimes. We further show that combining PTQMC with series resummation techniques yields stable and precise energy estimates in cases where the straightforward perturbative series fails. Finally, we propose the effective number of configurations, $e^{S}$ , as a global measure of perturbative wave-function complexity that can be directly extracted within PTQMC. We demonstrate that the saturation behavior of $e^{S}$ provides a more reliable indicator of the validity of perturbative expansions than energy convergence alone.
nucl-thPRC(2026)·4 citations
05
Probing $α$ clustering in $^{12} C$ at CSR energies using the Jet AA Microscopic Transport Model
Subhash Singha🇨🇳
We investigate the sensitivity of low-energy nuclear collisions to intrinsic nuclear structure by studying the interplay between initial-state geometry and final-state observables in C+C and C+Pb collisions at $s_{N N} = 2.36$ ~GeV, relevant for experiments at the Cooling Storage Ring (CSR) facility in Lanzhou and forthcoming experiments at the High Intensity heavy-ion Accelerator Facility (HIAF) in Huizhou. Calculations are performed within the Jet AA Microscopic Transport Model (JAM) using Woods--Saxon and triangular $α$ -clustered configurations for the $^{12} C$ nucleus. The initial geometry is characterized in terms of transverse size, compactness, eccentricities, and their ensemble-averaged fluctuations. We find that $α$ clustering leads to a more compact participant configuration than the Woods--Saxon case, while transverse-size and eccentricity fluctuations show only weak sensitivity to clustering. At this beam energy, radial observables remain sensitive to geometric compactness, with the ensemble-averaged proton mean transverse momentum $⟨ p_{T} ⟩$ enhanced for $α$ -clustered configurations, whereas pions show little sensitivity. The anisotropic response is examined using flow harmonic coefficients. We find an enhancement of the root-mean-square flow magnitudes, $v_{n} {2} = ⟨ v_{n}^{2} ⟩$ , for $α$ -clustered configurations at large $N_{p a r t}$ , while the ensemble-averaged fluctuation strength of individual harmonics remains small. Symmetric cumulants of the initial-state eccentricities show sensitivity to clustering, whereas the corresponding ensemble-averaged correlations among final-state flow harmonics do not exhibit a comparably strong separation. These results indicate that radial observables and correlation-based flow measurements provide complementary probes of $α$ clustering in low-energy nuclear collisions.
nucl-thhep-exnucl-ex0 citations

Affiliations

first authorsco-authorsvia INSPIRE

Correlations of Feed-down Hadrons in a Thermal Model

Comprehensive table of calculated Huff factors

New solution to the hyperon puzzle of neutron stars: Quantum many-body effects

Stochastic many-body perturbation theory for high-order calculations

Probing α clustering in 12C at CSR energies using the Jet AA Microscopic Transport Model

Affiliations

Probing $α$ clustering in $^{12} C$ at CSR energies using the Jet AA Microscopic Transport Model