Nuclear Theory·nucl-th

Thursday·July 4, 2024

6 papers—3 primary·3 cross-listed

01
Nuclear shell model study of neutrinoless double beta decay under Left-Right symmetric model
Dong-Liang Fang🇨🇳 · B. Alex Brown🇺🇸 · Fedor Šimkovic🇸🇰
We use the large scale nuclear shell model to calculate the nuclear matrix elements for the neutrino mediated neutrinoless double beta decay within the Left-Right symmetric model for four nuclei: $^{76}$ Ge, $^{82}$ Se, $^{130}$ Te and $^{136}$ Xe. We perform a systematic analysis on the general magnitude of different terms for related mechanisms. For the $η$ mechanism, we find that the weak magnetism $R$ term dominates the decay rate while the $p$ -wave effect is suppressed. While for the $λ$ mechanism, the $ω$ and the $q$ terms are with equal importance. For the latter $q$ term, important contributions from weak-magnetism MM part are observed. Finally, we give the constraints on the new physics parameters $m_{β β}$ , $λ$ and $η$ from current experiments.
nucl-thhep-phPRC(2024)·4 citations
02
Two-cluster approach to the properties of one- and two-neutron-halo nuclei
H. M. Maridi · Jagjit Singh · N. R. Walet · D. K. Sharp
In this work, we present a new approximate method for obtaining simple wave functions for the ground state of exotic nuclei with a neutron halo. We model the system as a two-cluster structure, treating the core and halo as inert objects. The relative wave function is expressed as a combination of simple harmonic oscillator states, with the oscillator parameter determined from the separation energy. Since these wave functions lack the expected exponential decay, we introduce a simple multiplicative renormalization factor based on the nuclear root mean square radius. This approach, combining oscillator wave functions and the renormalization factor, is then applied to calculate dipole strength distributions $d B (E 1, ε) / d ε$ and Coulomb dissociation cross section $d σ (E 1, ε) / d ε$ for several $1 n$ - and $2 n$ -halo nuclei. The results show excellent agreement with the available experimental data.
nucl-thPRC(2025)·3 citations
03
Assessing the joint effect of temperature and magnetic field on the neutron star equation of state
Luigi Scurto · Valéria Carvalho · Helena Pais · Constança Providência
In this work, we study the effect of strong magnetic fields on the equation of state (EoS) of warm, homogeneous, Neutron Star (NS) matter in beta equilibrium. NS matter is described within a relativistic mean field (RMF) approximation, including both models with non-linear meson terms or with density dependent nucleon-meson couplings. We first study the effect of magnetic fields and finite temperature on the EoS separately, finding that the effect of the latter to be significantly stronger than the one of the former. We then study the combined effect of magnetic fields and temperature on the internal composition. We show how both factors cause an increase in the proton fraction at low density and that, as long as the temperatures considered are not higher than 10 MeV, the effect of the magnetic field on the proton fraction is not small enough to be neglected.
nucl-thPRC(2024)·9 citations

Affiliations

first authorsco-authorsvia INSPIRE

Nuclear shell model study of neutrinoless double beta decay under Left-Right symmetric model

Two-cluster approach to the properties of one- and two-neutron-halo nuclei

Assessing the joint effect of temperature and magnetic field on the neutron star equation of state

Affiliations