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Nuclear Theory·nucl-th

Friday·April 18, 2025

4 papers—1 primary·3 cross-listed

All4Primary1Cross-lists3
  1. 01

    On the Inner Crusts of Neo-Neutron Stars: exotic light nuclei, diffusional and thermodynamical stability

    Mikhail V. Beznogov · Adriana R. Raduta

    Based on an extended nuclear statistical equilibrium model, we investigate the properties of non-accreted crusts of young and warm neo-neutron stars, i.e., of finite-temperature inhomogeneous dense matter in beta equilibrium. An interesting feature is the appearance, in the deep inner crust, of an extensive and almost pure layer of neutron-rich light nuclei that extends up to the density of the transition to homogeneous matter. Most probably, this layer emerges due to translational degrees of freedom of the nuclei. If confirmed, it will significantly impact the transport and elastic properties of the crust and its crystallization process. Then, we demonstrate that our inner crust is stable with respect to the diffusion of ions, which is in contrast with some of the predictions made in the literature for cold crusts. Finally, we show that clusterization completely exhausts the density instabilities that affect sub-saturated nuclear matter.

    nucl-thastro-ph.HEPRC(2026)·3 citations
  2. 02

    Precision mass measurements around Mo rule out ZrNb cycle formation in the rapid proton-capture process at type I X-ray bursts

    S. Kimura · M. Wada · C.Y. Fu · N. Fukuda · Y. Hirayama · D.S. Hou · S. Iimura · H. Ishiyama · Y. Ito · S. Kubono · K. Kusaka · S. Michimasa and 18 other authors

    The rapid proton-capture (-) process is one of the primary, explosive thermonuclear burning processes that drive type I X-ray bursts. A possible termination of the -process at around Mo was previously suggested by the formation of a ZrNb cycle. We report here precision mass measurements at around Mo, which have concluded the possibility of the cycle. The experiment was conducted using the multi-reflection time-of-flight spectrograph at RIKEN RI Beam Factory, and the masses of Y, Nb, Mo, Ru, and an isomer in Y were measured. For Mo, and Ru, and the isomeric state of Y, their masses are experimentally determined for the first time with uncertainties of . The mass precision of Y and Nb is improved to and , respectively. The new -separation energy of Mo, 1.434(83) MeV, unambiguously rules out the possibility of forming the ZrNb cycle. The X-ray burst simulation with the new masses shows that our measurements effectively remove the large final abundance uncertainties in the mass region. The new mass values improve the prediction power for the composition of the nuclear ashes in X-ray bursts.

    ↳ nucl-exastro-ph.HEnucl-thPRL(2025)·5 citations
  3. 03

    Lee Yang edge singularities of QCD in association with Roberge-Weiss phase transition and chiral phase transition

    Zi-yan Wan🇨🇳 · Yi Lu🇨🇳 · Fei Gao🇨🇳 · Yu-xin Liu🇨🇳

    We study the Quantum Chromodynamics (QCD) phase transitions in the complex chemical potential plane in the framework of Dyson-Schwinger equation approach, in the presence of a constant gluonic background field that represents confining dynamics. We solve the quark gap equation and the background field equation self consistently, which allows us to directly explore the confinement phase transition and furthermore, evaluate the impact of the back-coupling of confinement on chiral symmetry breaking. Moreover, within such a coupled framework towards the complex chemical potential region, we demonstrate the emergence of Roberge-Weiss (RW) symmetry and investigate the trajectory of Lee-Yang edge singularities (LYES). Our analysis reveals that the LYES scaling behavior is similar to our previous findings without the background field condensate. However, a significant difference from our earlier work is that the trajectory of LYES terminates when the imaginary part of the singularity becomes . We elaborate that this cut-off behavior is caused by the RW symmetry that is symmetric to the imaginary chemical potential .

    ↳ hep-phhep-thnucl-thPRD(2025)·8 citations
  4. 04

    Bayesian model-data comparison incorporating theoretical uncertainties

    Sunil Jaiswal🇺🇸 · Chun Shen🇺🇸 · Richard J. Furnstahl🇺🇸 · Ulrich Heinz🇺🇸 · Matthew T. Pratola🇺🇸

    Accurate comparisons between theoretical models and experimental data are critical for scientific progress. However, inferred physical model parameters can vary significantly with the chosen physics model, highlighting the importance of properly accounting for theoretical uncertainties. In this Letter, we present a Bayesian framework that explicitly quantifies these uncertainties by statistically modeling theory errors, guided by qualitative knowledge of a theory's varying reliability across the input domain. We demonstrate the effectiveness of this approach using two systems: a simple ball drop experiment and multi-stage heavy-ion simulations. In both cases incorporating model discrepancy leads to improved parameter estimates, with systematic improvements observed as additional experimental observables are integrated.

    ↳ hep-phnucl-thphysics.data-anPLB(2025)·7 citations

Affiliations

first authorsco-authorsvia INSPIRE