Nuclear Theory·nucl-th

Friday·May 15, 2026

10 papers—5 primary·5 cross-listed

01
[Submitted on 13 May 2026]
Taming nuclear size and shape effects in superallowed beta-decay
Bingcheng He🇺🇸 · Mikhail Gorchtein🇩🇪 · Matthias Heinz🇺🇸 · Ben Ohayon🇮🇱 · Lucas Platter🇺🇸 · Chien-Yeah Seng🇺🇸
We present the first combined analysis of the statistical rate function f in superallowed beta decays with ab initio calculations and data. We focus on C10 to 10B, 14O to 14N and 26mAl to 26Mg, all of which are important channels for the precise determination of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element Vud. Nuclear charge form factors are obtained by combining experimental data on nuclear charge radii and theory calculations of ratios of moments with the in-medium similarity renormalization group, while the beta decay form factors are derived from exact isospin relations. This enables a rigorous study of the nuclear shape dependence in the statistical rate function f and the quantification of its uncertainties from both experiment and theory. The calculation leads to a more precise test for the first-row CKM unitarity with reduced theoretical uncertainties. This work demonstrates a reliable strategy for combining nuclear many-body calculations with high-precision nuclear data to describe beta decays at tree level for precision tests of the Standard Model.
Comments:
11 pages, 6 figure, 5 tables
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2605.13985 [pdf]
3 citations
02
[Submitted on 13 May 2026]
Quantum Monte Carlo calculation of $δ_{C}$ in the superallowed beta decay of $^{10}$ C
Maria Piarulli · R. B. Wiringa · Alessandro Lovato · Garrett B. King · Saori Pastore
We perform an ab initio quantum Monte Carlo calculation of the isospin-symmetry-breaking correction $δ_{C}$ to the superallowed $β$ decay of $^{10} C$ . Using both phenomenological and chiral nuclear interactions, we evaluate the Fermi matrix element and quantify its deviation from the canonical $2$ value. The resulting $δ_{C}$ values lie in the range $\approx 0.15$ -- $0.25%$ and are consistent, within sizable uncertainties (approximately $34%$ -- $65%$ relative), across Hamiltonians, indicating no statistically significant dependence on the choice of nuclear interaction. The extracted values of $V_{u d}$ are also found to be compatible with current determinations within these uncertainties.
Comments:
25 pages, 3 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2605.14006 [pdf]
PRC(2026)·4 citations
03
[Submitted on 14 May 2026]
Bayesian analysis of density profile of light dark matter elucidating the properties of dark matter admixed neutron stars in the presence of hyperons
Debashree Sen🇰🇷 · Atanu Guha🇰🇷 · Chang Ho Hyun🇰🇷
We study the impact of symmetry energy ( $S$ ), hyperons, and dark matter (DM) on structural and oscillatory properties of neutron stars (NSs). Uncertainty from hadronic equation of state for NSs is considered with 15 relativistic mean field models having slope parameter ( $L_{0}$ ) of $S$ in range $40 - 120$ MeV. DM admixed NSs (DMANSs) are described with feeble interaction between light DM fermions ( $χ$ ) with hadronic matter in the presence of hyperons via scalar ( $η$ ) and vector ( $ξ$ ) dark mediators. The masses $m_{χ}$ , $m_{η}$ and $m_{ξ}$ are related by self-interaction constraints from bullet cluster. DM self-interaction couplings are related to $m_{χ}$ by relic density constraint. The DM density is taken as an exponential function of baryon density with a free parameter $α$ . Uncertainty from DM model is incorporated by exploring the dependence on $m_{χ}$ and $α$ . Several DM search experiments have almost ruled out the existence of massive DM ( $≳$ GeV). Lately, pursuit for sub-GeV DM has attracted significant attention. Therefore, we consider $m_{χ} <$ 1 GeV and $α \leq$ 0.1 such that the contribution of DM to the total mass of the DMANSs is $< 10%$ . Comparing our results with various astrophysical constraints, we find that the HESS J1731-347 and GW170817 data are very important in determining the presence of light DM in NSs in moderate amount, relevant in the range $L_{0} ≲$ 58 MeV. Employing models of DMANSs that satisfy several observational data, we infer with Bayesian analysis, the likely ranges of $m_{χ}$ and $α$ are almost independent of the underlying hadronic model within 40 MeV $≲$ $L_{0}$ $<$ 58 MeV. In the absence of DM and with the most probable values of $m_{χ}$ and $α$ obtained from the Bayesian inference, we calculate the frequencies of non-radial $f$ - and $p_{1}$ -modes oscillation of NSs/DMANSs.
Comments:
22 pages, 9 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th)
arXiv:
2605.14447 [pdf]
0 citations
04
[Submitted on 14 May 2026]
Fourth order correlation of baryon number and electric charge as a better magnetometer of QCD
Shijun Mao🇨🇳 · Shuai Yang🇨🇳 · Sicheng Lin🇨🇳 · Xinran Yang🇨🇳 · Guoyun Shao🇨🇳 · Wen-Chao Zhang🇨🇳
This work focuses on the fourth order correlations $χ_{31}^{B Q}$ , $χ_{31}^{QB}$ , $χ_{22}^{B Q}$ , $χ_{31}^{B S}$ , $χ_{31}^{S B}$ , $χ_{22}^{B S}$ , $χ_{31}^{QS}$ , $χ_{31}^{S Q}$ , $χ_{22}^{QS}$ , $χ_{211}^{B QS}$ , $χ_{211}^{QB S}$ , $χ_{211}^{S B Q}$ of baryon number $B$ , electric charge $Q$ and strangeness $S$ at finite temperature, magnetic field and vanishing quark chemical potential. The study is carried out in the framework of a three-flavor PNJL model, considering both cases with and without inverse magnetic catalysis effect. We find that, fourth order correlations $χ_{31}^{B Q}$ at chiral restoration phase transition is more sensitive to the magnetic field than other second order and fourth order correlations and fluctuations, and can be served as a more effective magnetometer of QCD.
Comments:
12 pages, 10 figures, 1 table. arXiv admin note: text overlap with arXiv:2504.14532
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2605.14674 [pdf]
1 citation
05
[Submitted on 14 May 2026]
Skyrme SV density-functional analysis of the $2 ν β β$ decay in $^{76}$ Ge
Jan Miśkiewicz🇵🇱 · Jakub Wysocki🇵🇱 · Wojciech Satuła🇵🇱
We present a theoretical study of the two-neutrino $0^{+} \to 0^{+}$ double beta decay of $^{76}$ Ge within the No-Core Configuration-Interaction framework based on the Skyrme SV density functional. We analyze three allowed decay scenarios distinguished by the $[n, m] \equiv [(ν g_{9/2})^{n}, (π g_{9/2})^{m}]$ occupancy of the $0 g_{9/2}$ intruder orbital, which remains conserved to high precision, as well as by the triaxiality of the daughter nucleus. The resulting $2 ν β β$ nuclear matrix element is found to depend strongly on the scenario. For the energetically favored $[4, 2]$ occupancy, we obtain $∣ M^{2 ν} ∣ = 0.069 (7)$ ~MeV $^{- 1}$ . For the $[6, 0]$ occupancy, the matrix element further depends on the triaxiality parameter $γ$ of the two coexisting, closely lying minima in $^{76}$ Se, yielding $∣ M^{2 ν} ∣ = 0.040 (4)$ ~MeV $^{- 1}$ at $γ = 17. 7^{\circ}$ and $∣ M^{2 ν} ∣ = 0.22 (2)$ ~MeV $^{- 1}$ at $γ = 41. 9^{\circ}$ . The latter result is consistent with the empirical value reported by A. S. Barabash, $∣ M^{2 ν} ∣ = 0.204 (14)$ ~MeV $^{- 1}$ , while the two former results are comparable to existing calculations based on energy-density-functional frameworks. Our calculations reveal challenges in the precise determination of the $∣ M^{2 ν} ∣$ for the $^{76}$ Ge decay. The structural complexity, triaxiality, and shape coexistence identified in the analyzed nuclei imply a strong sensitivity to fine details of the interaction and configuration mixing. This, in turn, explains the difficulties in theoretical modeling of the $∣ M^{2 ν} ∣$ matrix elements for the $^{76}$ Ge decay, which vary by almost an order of magnitude in the available literature.
Comments:
12 pages, 13 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2605.14813 [pdf]
0 citations

Affiliations

first authorsco-authorsvia INSPIRE

Taming nuclear size and shape effects in superallowed beta-decay

Quantum Monte Carlo calculation of δC​ in the superallowed beta decay of 10C

Bayesian analysis of density profile of light dark matter elucidating the properties of dark matter admixed neutron stars in the presence of hyperons

Fourth order correlation of baryon number and electric charge as a better magnetometer of QCD

Skyrme SV density-functional analysis of the 2νββ decay in 76Ge

Affiliations

Quantum Monte Carlo calculation of $δ_{C}$ in the superallowed beta decay of $^{10}$ C

Skyrme SV density-functional analysis of the $2 ν β β$ decay in $^{76}$ Ge