Nuclear Theory·nucl-th

Wednesday·September 10, 2025

10 papers—5 primary·5 cross-listed

01
Bayesian Analysis of the Neutron Star Equation of State and Model Comparison: Insights from PSR J0437+4715, PSR J0614+3329, and Other Multi-Physics Data
Sk Md Adil Imam🇨🇱 · N. K. Patra🇨🇳
We perform a comprehensive Bayesian analysis to constrain the neutron star (NS) equation of state (EoS) using a wide range of terrestrial and astrophysical data. The terrestrial inputs include quantities related to symmetric nuclear matter (SNM) and symmetry energy up to two times saturation density ( $ρ_{0} \sim$ 0.16 fm $^{- 3}$ ), derived from finite nuclei and heavy-ion collisions (HICs). The astrophysical constraints incorporate NS radii and tidal deformabilities from recent NICER observations and GW170817, respectively. We consider five different EoS models: Taylor, $n /3$ , Skyrme, RMF, and sound speed(CS), are analyzed by sequentially updating the priors with (i) $χ$ EFT based pure neutron matter, (ii) terrestrial, empirical and earlier astrophysical data, (iii) case (ii) including NICER radii of PSR J0437+4715 and J0614+3329, (iv) all data combined, and (v) excluding empirical nuclear inputs. We also perform Bayesian model comparison which favors the Skyrme model under all combined data (scenario (iv)), yielding tight constraints on symmetry energy parameters: $L_{0} = 56 \pm 3$ ~MeV, $K_{sym 0} = - 132 \pm 15$ ~MeV and also on SNM parameters: $K_{0} = 265 \pm 12$ ~MeV, $Q_{0} = - 366 \pm 43$ ~MeV. The mass-radius and mass-tidal deformability posterior distributions are also well constrained. The radius and tidal deformability of a $1.4 M_{⊙}$ neutron star are found to be $R_{1.4} = 11.85 \pm 0.11$ ~km and $Λ_{1.4} = 354 \pm 25$ , respectively.
nucl-thastro-ph.HEastro-ph.SRgr-qc+1PRD(2025)·7 citations
02
Quantum Monte Carlo calculation of $δ_{NS}$ in $^{10}$ C using an effective field theory approach
Garrett B. King🇺🇸 · Joseph Carlson🇺🇸 · Abraham R. Flores🇺🇸 · Stefano Gandolfi🇺🇸 · Emanuele Mereghetti🇺🇸 · Saori Pastore🇺🇸 · Maria Piarulli🇺🇸 · Robert B. Wiringa🇺🇸
We compute radiative corrections to the superallowed $β$ decay of $^{10} C$ in an effective field theory approach using nuclear matrix elements obtained from quantum Monte Carlo calculations. These corrections are an important ingredient in the extraction of the Cabibbo-Kobayashi-Masakawa quark mixing matrix element $V_{u d}$ , and the role of this work is to illuminate the uncertainties arising from nuclear structure. Our results provide good agreement with both the traditional extraction of $V_{u d}$ , as well as with a more recent evaluation performed using the no-core shell model and a dispersion formalism. The dominant uncertainty in this approach is the presence of two unknown low-energy constants that enter into the relevant nuclear matrix elements. Future determinations of these low-energy constants -- either from QCD or modeling them with two nucleon amplitudes -- would improve the precision of the extraction in this formalism.
nucl-thPRC(2026)·10 citations
03
$K^{*} (892)$ Resonance Suppression in Ar+Sc Collisions at SPS Energies
Amine Chabane🇩🇪 · Tom Reichert🇩🇪 · Jan Steinheimer🇩🇪 · Marcus Bleicher🇩🇪
We investigate the production and suppression of short-lived $K^{*} (892)$ resonances in p+p and Ar+Sc collisions at CERN-SPS energies ( $s_{NN} =$ 8.8, 11.9, and 16.8~GeV) using the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model. We present multiplicities, rapidity and transverse momentum distributions, and analyze the $K^{*} / K$ yield ratios as a function of energy and centrality. We further estimate the time interval between chemical and kinetic freeze-out using the experimental method. A detailed comparison with recent NA61/SHINE data demonstrates that the UrQMD model captures the essential features of resonance dynamics, although the very strong resonance suppression in central collisions observed in the data cannot be quantitatively reproduced.
nucl-thPRC(2026)·1 citation
04
$B (E 2; 2_{1}^{+} \to 0_{1}^{+})$ anomaly in $^{166}$ Os
Chen-guang Zhang🇨🇳 · Suo-chang Jin🇨🇳 · Tie Wang🇨🇳 · Tao Wang🇨🇳
Recently, the very small $B (E 2; 2_{1}^{+} \to 0_{1}^{+})$ value was found in $^{166}$ Os, which is 7(4) W.u. \textbf{and} much smaller than the values of adjacent nuclei $^{168, 170}$ Os, 74(13) W.u. and 97(9) W.u.. With the help of a new technique ``SU(3) analysis" and a new explanatory framework of the B(E2) anomaly, it was found that, the $B (E 2; 2_{1}^{+} \to 0_{1}^{+})$ anomaly really can exist. In this paper, we discuss the $B (E 2; 2_{1}^{+} \to 0_{1}^{+})$ anomaly in $^{166}$ Os for the first time. Four results are used to fit the experimental data in $^{166, 168, 170}$ Os successfully. This implies that the level-crossing or level-anticrossing explanation is more reasonable.
nucl-th0 citations
05
Nuclear Data Adjustment for Nonlinear Applications in the OECD/NEA WPNCS SG14 Benchmark -- A Bayesian Inverse UQ-based Approach for Data Assimilation
Christopher Brady (1) · Xu Wu (1) ((1) North Carolina State University)
The Organization for Economic Cooperation and Development (OECD) Working Party on Nuclear Criticality Safety (WPNCS) proposed a benchmark exercise to assess the performance of current nuclear data adjustment techniques applied to nonlinear applications and experiments with low correlation to applications. This work introduces Bayesian Inverse Uncertainty Quantification (IUQ) as a method for nuclear data adjustments in this benchmark, and compares IUQ to the more traditional methods of Generalized Linear Least Squares (GLLS) and Monte Carlo Bayes (MOCABA). Posterior predictions from IUQ showed agreement with GLLS and MOCABA for linear applications. When comparing GLLS, MOCABA, and IUQ posterior predictions to computed model responses using adjusted parameters, we observe that GLLS predictions fail to replicate computed response distributions for nonlinear applications, while MOCABA shows near agreement, and IUQ uses computed model responses directly. We also discuss observations on why experiments with low correlation to applications can be informative to nuclear data adjustments and identify some properties useful in selecting experiments for inclusion in nuclear data adjustment. Performance in this benchmark indicates potential for Bayesian IUQ in nuclear data adjustments.
nucl-thcs.LG0 citations
06
Energy loss baseline for light hadrons in oxygen-oxygen collisions at $s_{NN} = 5.36 TeV$
Aleksas Mazeliauskas🇩🇪
I present predictions for inclusive charged hadron spectra in minimum-bias proton-proton and oxygen-oxygen collisions at a centre-of-mass energy of $s_{NN} = 5.36 TeV$ , assuming no final-state interactions. Using next-to-leading order perturbative QCD matrix elements, along with state-of-the-art (nuclear) parton distribution and fragmentation functions, I establish a baseline for the nuclear modification factor $R_{AA}^{h}$ in oxygen-oxygen collisions in the absence of quenching. Theoretical uncertainties in this baseline are found to be substantial for transverse momenta below $20 GeV$ . In the intermediate range $20 GeV ≲ p_{T}^{h} ≲ 70 GeV$ , these uncertainties are significantly reduced to approximately 5\%. At higher momenta ( $p_{T}^{h} ≳ 70 GeV$ ), however, predictions exhibit a marked spread due to differences between fragmentation functions, reflecting varying assumptions about isospin symmetry. Finally, I show that considering neon-neon collisions in the initial state or neutral pions in the final state does not appreciably change the nuclear modification factor.
↳ hep-phnucl-exnucl-thPLB(2026)·10 citations
07
Recursive algorithm for constructing antisymmetric fermionic states in first quantization mapping
E. Rule🇺🇸 · I. A. Chernyshev🇺🇸 · I. Stetcu🇺🇸 · J. Carlson🇺🇸 · R. Weiss🇺🇸
We devise a deterministic quantum algorithm to produce antisymmetric states of single-particle orbitals in the first quantization mapping. Unlike sorting-based antisymmetrization algorithms, which require ordered input states and high Clifford-gate overhead, our approach initializes the state of each particle independently. For a system of $η$ particles and $N$ single-particle states, our algorithm prepares antisymmetrized states of non-trivial localized (e.g., Hartree-Fock) orbitals using $O (η^{2} N)$ $T$ -gates, outperforming alternative algorithms when $η ≲ N$ . To achieve such scaling, we require $O (N)$ dirty ancilla qubits for intermediate calculations. Knowledge of the single-particle states to be antisymmetrized can be leveraged to further improve the efficiency of the circuit, and a measurement-based variant reduces gate cost by roughly a factor of two. We show example circuits for two- and three-particle systems and discuss the generalization to an arbitrary number of particles. For a specific three-particle example, we decompose the circuit into Clifford $+ T$ gates and study the impact of noise on the prepared state.
↳ quant-phnucl-thphysics.chem-phQuantum(2026)·1 citation
08
Predictions for $R_{AA}$ in 5.36 TeV C+C, O+O, and Ne+Ne collisions at the LHC
B.G. Zakharov🇷🇺
Experiments on collisions of light nuclei at $s = 5.36$ TeV have recently begun at the LHC. In this regard we make predictions for nuclear modification factor $R_{AA}$ in 5.36 TeV C+C, O+O, and Ne+Ne collisions for scenarios with and without quark-gluon plasma formation in $pp$ collisions. We find a sizeable difference in $R_{AA}$ for these two scenarios, which grows with decreasing atomic number. This says that data on $R_{AA}$ for light nuclei could potentially give information on the presence of jet quenching in $pp$ collisions.
↳ hep-phnucl-thPisma Zh.Eksp.Teor.Fiz.(2025)·2 citations
09
Illuminating dark matter admixed in neutron stars with simultaneous mass-radius constraints
Nai-Bo Zhang🇨🇳 · Bao-An Li🇺🇸 · Jia-Yu Zhang🇨🇳 · Wei-Na Shen🇨🇳 · Hui Zhang🇨🇳
We investigate how simultaneous mass and radius measurements of massive neutron stars (NSs) can help constrain properties of dark matter (DM) possibly admixed in them. Within a fermionic DM model that interacts only through gravitation, along with a well-constrained nuclear matter equation of state, we show that the simultaneous mass and radius measurement of PSRJ0740+6620 reduces the uncertainty of DM central energy density by more than 50\% compared to the results obtained from using the two observables independently, while other DM parameters remain unconstrained. Additionally, we find that the DM fraction $f_{D}$ should be smaller than 2\% when constrained by the observed NS maximum mass alone, and it could be even smaller than 0.3\% with the simultaneous measurement of mass and radius, supporting the conclusion that only a small amount of DM exists in DM admixed neutron stars (DANS).
↳ astro-ph.HEnucl-thSymmetry(2025)·11 citations
10
Excitation Spectra of the $^{12} C (p, d)$ Reaction near the $η^{'}$ -Meson Emission Threshold Measured in Coincidence with High-Momentum Protons
R. Sekiya🇯🇵 · K. Itahashi🇯🇵 · Y. K. Tanaka🇯🇵 · S. Hirenzaki🇯🇵 · N. Ikeno🇯🇵 · V. Metag🇩🇪 · M. Nanova🇩🇪 · J. Yamagata-Sekihara🇯🇵 · V. Drozd🇳🇱 · H. Ekawa🇯🇵 · H. Geissel🇩🇪 · E. Haettner🇩🇪 and 65 other authors
The missing mass of the $^{12} C (p, d)$ reaction has been measured near the $η^{'}$ -meson emission threshold in coincidence with a high-momentum proton to selectively collect $η^{'}$ - $^{11} C$ mesic nucleus formation events at GSI, Germany. A 2.5 GeV proton excites a carbon nucleus to form an $η^{'}$ -mesic nucleus emitting a deuteron forward with an energy of $\sim 1.6$ GeV. The deuteron is momentum-analyzed by the Fragment Separator used as a high-resolution spectrometer to deduce the excitation energy of the residual system. The large-acceptance detector WASA surrounding the target identifies high-momentum protons emitted in the decay of the $η^{'}$ -mesic nucleus. The measured semi-exclusive spectrum exhibits structures below the threshold though the statistical significance is limited. The spectrum is fitted by theoretically calculated spectra varying optical-potential parameters of the $η^{'}$ -nucleus interaction. The analysis results indicate $η^{'}$ -mesic nuclei formation for the real potential depth of $\sim - 61$ MeV with a local statistical significance of $3.5 σ$ and, taking into account the look-elsewhere effect, a global significance of $2.1 σ$ .
↳ nucl-exnucl-thPRL(2026)·11 citations

Affiliations

first authorsco-authorsvia INSPIRE