Nuclear Theory·nucl-th

Friday·February 28, 2025

14 papers—8 primary·6 cross-listed

01
[Submitted on 27 Feb 2025]
Sensitivity of neutron drip lines and neutron star properties to the symmetry energy
Yeunhwan Lim🇰🇷 · Jeremy W. Holt🇺🇸
We investigate the influence of the nuclear symmetry energy and its density slope parameter on the neutron dripline and neutron star properties using a semi-classical liquid drop model (LDM) and energy density functionals constrained by chiral effective field theory. To analyze finite nuclei and mass tables, the nuclear symmetry energy at saturation density is fixed, and the surface tension is determined to minimize the root-mean-square deviation of the total binding energy for 2208 nuclei. Correlations between symmetry energy parameters and neutron driplines, crust-core transition densities, and the radii of $1.4 \msun$ neutron stars are explored using the LDM framework. Additionally, we examine the relationship between macroscopic properties, such as neutron star radii ( $R_{1.4}$ ), and microscopic properties, including the number of isotopes and the last bound nucleus for $Z = 28$ , within the LDM context.
Comments:
14 pages, 14 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2502.19762 [pdf]
PRC(2026)·6 citations
02
[Submitted on 27 Feb 2025]
Beta decay and electron capture rates on manganese isotopes in astrophysical environments
R. Shehzadi · J.-U. Nabi · F. Farooq
The isotopes of manganese in the mass range A equal to 53 to 63 are abundant in the core material of high mass stars and are believed to be of prime importance in the progression of the pre collapse phases. During these late evolutionary phases, nuclear processes associated with weak interactions, including decay and electron capture (EC) on these isotopes, significantly alter the Ye (lepton to baryon ratio) of the cores composition. The temporal change of this parameter is one of the basic elements to simulate a successful explosion. Hence, the decay and EC rates of manganese (Mn) nuclides may serve as an important input in the simulation codes of core collapse supernova. In this paper, we focus on the study of the weak decay characteristics of 55 63Mn nuclides. The strength distributions of Gamow Teller transitions in the directions of decay and EC for these isotopes were calculated employing the proton neutron quasi particle random phase approximation (pn QRPA) model. The decay half life values of Mn isotopes under terrestrial conditions were computed and compared with measured data and previous calculations. The pn QRPA estimated half lives are in good agreement with the experimental values. The and EC rates were later calculated covering a large range of stellar temperatures (001 30) 109 K and densities (10 1011) g/cm3.
Comments:
26 Pages, 5 Table, 5 Figures
Subjects:
Nuclear Theory (nucl-th); Solar and Stellar Astrophysics (astro-ph.SR)
arXiv:
2502.19813 [pdf]
New Astron.(2023)·3 citations
03
[Submitted on 27 Feb 2025]
Investigation of weak-rates for odd-A nuclei for presupernova simulations
Muhammad Riaz🇵🇰 · Jameel-Un Nabi🇵🇰 · Muhammad Majid🇵🇰
Calculating weak decay rates under stellar conditions for studying presupernova evolution of massive stars is a challenging task. Here we show the importance of odd A nuclei for presupernova simulations. In order to calculate the required nuclear matrix elements we apply the pn QRPA model in a deformed basis. Nuclear deformation, thought to play an integral role in calculation of associated weak decay rates, is taken into account in our model. We calculate Gamow Teller (GT) strength distributions, emission and positron capture rates for selected odd A nuclei. Our model does not employ the Brink Axel hypothesis as used in previous calculations of weak decay rates and we perform a state by state microscopic calculation of GT strength distributions from all parent excited states. Our calculated decay rates are in good agreement with large scale shell model calculations.
Comments:
13 Pages , 2 Tables, 5 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2502.19837 [pdf]
Braz.J.Phys.(2021)·0 citations
04
[Submitted on 27 Feb 2025]
Bayesian inferences on covariant density functionals from multimessenger astrophysical data: Nucleonic models
Jia-Jie Li (Southwest U., Chongqing) · Yu Tian (Southwest U., Chongqing) · Armen Sedrakian (FIAS, Frankfurt and U. Wroclaw)
[Background] Bayesian inference frameworks incorporating multi-messenger astrophysical constraints have recently been applied to covariant density functional (CDF) models to constrain their parameters. Among these, frameworks utilizing CDFs with density-dependent meson-nucleon couplings furnishing the equation of state (EoS) of compact star (CS) matter have been explored. [Purpose] The aforementioned inference framework has not yet incorporated astrophysical objects with potentially extreme high masses or ultra-small radii among its constraints, leaving its flexibility and predictive power under such extreme parameters still unknown. [Method] We apply the Bayesian inference framework based on CDFs with density dependent couplings. The astrophysical data is expanded to include not only the latest multi-messenger constraints from NICER and gravitational wave events but also the highest measured mass to date for the ``black widow" pulsar PSR J0952-0607 and the mass-radius estimates for the ultra-compact, low-mass object HESS J1731-347. [Results] Our systematic Bayesian analysis indicates that our CDF models can support higher maximum masses for CSs, reaching up to $2.4$ - $2.5 M_{⊙}$ . However, achieving sufficient softening of the EoS in the low-density regime to accommodate the HESS J1731-347 data remains challenging. Nonetheless, we are able to impose tighter constraints on the parameter space of CDF models, ensuring consistency with current nuclear experimental and astrophysical data. [Conclusions] CDF models with density-dependent meson-nucleon couplings encompass a wide range of nuclear and astrophysical phenomena, providing a robust theoretical framework for interpreting compact objects. However, the predicted lower limit for the radii of low-mass stars is approximately 12 km, which stems from the restricted degrees of freedom in the isovector sector.
Comments:
25 pages, 14 figures, matches published version
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
arXiv:
2502.20000 [pdf]
PRC(2025)·14 citations
05
[Submitted on 27 Feb 2025]
The $η^{'} N$ interaction from the $η^{'} p$ correlation function
Natsumi Ikeno🇯🇵
We evaluate for the first time the $η^{'} p$ femtoscopic correlation function to study the $η^{'} N$ interaction. We find it extremely sensitive to the value of the $η^{'} p$ scattering length, for which at present there exists only very limited information, not even knowing its sign. The measurement of this correlation function would provide much valuable information on the $η^{'} N$ interaction, which could then also be used to settle the issue of possible $η^{'}$ nucleus bound states, an issue attracting much attention in the nuclear physics community.
Comments:
7 pages, 3 figures, 2 tables
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2502.20020 [pdf]
EPJA(2025)·7 citations
06
[Submitted on 27 Feb 2025]
Electromagnetic form factors of $^{6}$ Li, $^{7}$ Li, and $^{7}$ Be in cluster effective field theory
Son T. Nguyen
Effective field theory (EFT) provides a powerful model-independent theoretical framework for illuminating complicated interactions across a wide range of physics areas and subfields. In this work, we consider the low-energy deuteron-Helium-4, triton-Helium-4, and helion-Helium-4 systems at low energies in cluster EFT. In particular, we focus on the deuteron + Helium-4 cluster configuration of the Lithium-6 nucleus, the triton + Helium-4 cluster configuration of the Lithium-7 nucleus, and the Helium-3-Helium-4 configuration of the Beryllium-7 nucleus, respectively. We illustrate how to directly extract the asymptotic normalization coefficient and several observables using experimental measurement of the electromagnetic form factors of these nuclei.
Comments:
30 pages, 12 figures, 6 tables
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2502.20202 [pdf]
1 citation
07
[Submitted on 27 Feb 2025]
Inferring the Equation of State from Neutron Star Observables via Machine Learning
N. K. Patra🇨🇳 · Tuhin Malik🇵🇹 · Helena Pais🇵🇹 · Kai Zhou🇨🇳 · B. K. Agrawal🇮🇳 · Constança Providência🇵🇹
We have conducted an extensive study using a diverse set of equations of state (EoSs) to uncover strong relationships between neutron star (NS) observables and the underlying EoS parameters using symbolic regression method. These EoS models, derived from a mix of agnostic and physics-based approaches, considered neutron stars composed of nucleons, hyperons, and other exotic degrees of freedom in beta equilibrium. The maximum mass of a NS is found to be strongly correlated with the pressure and baryon density at an energy density of approximately 800 MeV.fm $^{- 3}$ . We have also demonstrated that the EoS can be expressed as a function of radius and tidal deformability within the NS mass range 1-2 $M_{⊙}$ . These insights offer a promising and efficient framework to decode the dense matter EoS directly from the accurate knowledge of NS observables.
Comments:
9 pages, 5 figures, 2 tables (Published in Physics Letters B)
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2502.20226 [pdf]
PLB(2025)·19 citations
08
[Submitted on 27 Feb 2025]
Global Framework for Emulation of Nuclear Calculations
Antoine Belley · Jose M. Munoz · Ronald F. Garcia Ruiz
We introduce a hierarchical framework that combines ab initio many-body calculations with a Bayesian neural network, developing emulators capable of accurately predicting nuclear properties across isotopic chains simultaneously and being applicable to different regions of the nuclear chart. We benchmark our developments using the oxygen isotopic chain, achieving accurate results for ground-state energies and nuclear charge radii, while providing robust uncertainty quantification. Our framework enables global sensitivity analysis of nuclear binding energies and charge radii with respect to the low-energy constants that describe the nuclear force.
Subjects:
Nuclear Theory (nucl-th); Machine Learning (cs.LG)
arXiv:
2502.20363 [pdf]
PRL(2026)·12 citations

Affiliations

first authorsco-authorsvia INSPIRE