Related papers: Electron Capture Rates of Mid-fp Shell Nuclei for …
The importance of microphysical inputs from laboratory nuclear experiments and theoretical nuclear structure calculations in the understanding of the core collapse dynamics, and the subsequent supernova explosion, is largely recognized in…
Gamow-Teller (GT) strength in $^{40}$Ar is studied by shell-model calculations with monopole-based universal intearction, which has tensor components of $\pi$\rho$-meson exchanges. Calculated GT strength is found to be consistent with the…
Gamow-Teller transitions in isotopes of chromium play a consequential role in the presupernova evolution of massive stars. $\beta$-decay and electron capture rates on chromium isotopes significantly affect the time rate of change of lepton…
At finite temperatures ($\geq 10^7$K), $^{76}$Se is abundant in the core of massive stars and electron capture on $^{76}$Se has a consequential role to play in the dynamics of core collapse. The present work may be classified into two main…
During the presupernova evolution of massive stars, the isotopes of iron, $^{54,55,56}$Fe, are advocated to play a key role inside the cores primarily decreasing the electron-to-baryon ratio ($Y_{e}$) mainly via electron capture processes…
Electron capture and positron decay rates are calculated for neutron-deficient Kr and Sr waiting point nuclei in stellar matter. The calculation is performed within the framework of pn-QRPA model for rp-process conditions. Fine tuning of…
Accurate estimate of neutrino energy loss rates are needed for the study of the late stages of the stellar evolution, in particular for cooling of neutron stars and white dwarfs. Proton-neutron quasi-particle random phase approximation…
Neutrino reactions on $^{40}$Ar via charged and neutral currents for detecting solar and core collapsing supernovae (SNe) neutrinos and the Gamow Teller strength are calculated by considering the high-lying excited states up to a few tens…
We calculate Gamow-Teller strength distributions for $\beta \beta$-decay nuclei $^{76}$Ge and $^{82}$Se using the deformed pn-QRPA model. We use a deformed Nilsson basis and consider pairing correlations within the deformed BCS theory.…
We link complex many-body correlations, which play a decisive role in the structural properties of atomic nuclei, to the electron capture occurring during star evolution. The recently developed finite-temperature response theory, taking…
The Gamow-Teller strength for the transition from the ground state of 13C to the T=1/2, J^pi=3/2- excited state at 3.51 MeV in 13N is extracted via the 13C(3He,t) reaction at 420 MeV. In contrast to results from earlier (p,n) studies on…
It has been suggested that hydrogen ingestion into the helium shell of massive stars could lead to high $^{13}$C and $^{15}$N excesses when the shock of a core-collapse supernova passes through its helium shell. This prediction questions…
We have evaluated the electron capture rates on $^{20}$Ne, $^{20}$F, $^{24}$Mg, $^{24}$Na and the $\beta$ decay rates for $^{20}$F and $^{24}$Na at temperature and density conditions relevant for the late-evolution stages of stars with…
A method for calculation of Gamow-Teller transition rates is developed by using the concept of the Projected Shell Model (PSM). The shell model basis is constructed by superimposing angular-momentum-projected multi-quasiparticle…
Nuclear weak rates in stellar environments are obtained by shell-model calculations including Gamow-Teller (GT) and spin-dipole transitions, and applied to nuclear weak processes in stars. The important roles of accurate weak rates for the…
During the late stages of gravitational core-collapse of massive stars, extreme isospin asymmetries are reached within the core. Due to the lack of microscopic calculations of electron capture (EC) rates for all relevant nuclei, in general…
In the late progressive stages of heavy stars, electron capture and $\beta^\pm$-decay are the governing processes. The weak rates are essential inputs for modeling the stages of high-mass stars before supernova explosions. As per results…
We investigate the Gamow-Teller strength distributions in the electron-capture direction in nuclei having mass A=90-97, assuming a 88Sr core and using a realistic interaction that reasonably reproduces nuclear spectroscopy for a wide range…
In our calculation of neutron star crust heating we include several key new model features. In earlier work electron capture (EC) only allowed neutron emission from the daughter ground-state; here we calculate, in a deformed QRPA model, EC…
From the modeling and simulation results of presupernova evolution of massive stars, it was found that isotopes of iron, $^{54,55,56}$Fe, play a significant role inside the stellar cores, primarily decreasing the electron-to-baryon ratio…