相关论文: Competition of electron capture and beta-decay rat…
A detailed model is constructed for the calculation of electron capture rates of some fp-shell nuclei for situations prevailing in pre-supernova and collapse phases of the evolution of the core of massive stars leading to supernova…
At densities between 10^8 and 10^10} g/cm^3 electron capture in a presupernova collapse is believed to mainly occur on odd-odd nuclei. We have derived the rates for six of the most important electron capturing nuclei, {54,56,58}Mn and…
Based on large-scale shell model calculations we have determined the electron capture, positron capture and beta-decay rates on more than 100 nuclei in the mass range A=45-65. The rates are given for densities \rho Y_e =10^7-10^{10}…
We present Gamow-Teller strength distributions from shell model Monte Carlo studies of fp-shell nuclei that may play an important role in the pre-collapse evolution of supernovae. We then use these strength distributions to calculate the…
We have calculated the Gamow-Teller strength distributions for the ground states and first excited states in 55Co and 56Ni. These calculations have been performed by shell model diagonalization in the pf shell using the KB3 interaction. The…
Calculations for electron capture rates on nuclei with atomic numbers between $Z=20$ and $Z=52$ are performed in a self-consistent finite-temperature covariant energy density functional theory within the relativistic quasiparticle…
Electron captures on nuclei play an important role in the collapse of stellar core in the stages leading to a type-II supernova. Recent observations of subluminous Type II-P supernovae (e.g. 2005cs, 2003gd, 1999br) were able to rekindle the…
Improved values for stellar weak interaction rates have been recently calculated based upon a large shell model diagonalization. Using these new rates (for both beta decay and electron capture), we have examined the presupernova evolution…
This paper presents a systematic evaluation of the ability of theoretical models to reproduce experimental Gamow-Teller transition strength distributions measured via (n,p)-type charge-exchange reactions at intermediate beam energies. The…
A detailed model for the calculation of beta decay rates of the $fp$ shell nuclei for situations prevailing in pre-supernova and collapse phases of evolution of the core of massive stars leading to supernova explosion has been extended for…
Electron-capture rates at different density and temperature conditions are evaluated for a set of pf-shell nuclei representative of the constituents in presupernova formations. The nuclear structure part of the problem is described within a…
The Gamow-Teller (GT) transitions within massive stars play sumptuous role in the dynamics of core collapse supernovae. GT strength distributions and electron capture rates have been calculated for odd-A nucleus $^{59}$Co within the…
We present shell model calculations of electron capture strength distributions in A=28 nuclei and computations of the corresponding capture rates in supernova core conditions. We find that in these nuclei the Brink-Axel hypothesis for the…
Recent shell-model calculations of weak-interaction rates for nuclei in the mass range A = 45 - 65 have resulted in substantial revisions to the hitherto standard set of Fuller, Fowler, & Newman (FFN). In particular, key electron-capture…
The half lives are calculated for the process of $\beta^\pm$ decay and electron capture for nuclei in mass range $\sim$ 65 - 100 relevant for the core of a massive star at late burning stage of steller evolution that leads to supernova…
Recent experimental results have confirmed a possible reduction in the GT$_+$ strengths of pf-shell nuclei. These proton-rich nuclei are of relevance in the deflagration and explosive burning phases of Type Ia supernovae. While prior GT…
Supernova simulations to date have assumed that during core collapse electron captures occur dominantly on free protons, while captures on heavy nuclei are Pauli-blocked and are ignored. We have calculated rates for electron capture on…
Electron capture and beta-decay rates on nuclei in the mass range A=45-65 play an important role in many astrophysical environments. The determination of these rates by large-scale shell model calculations is desirable, but it requires to…
Electron capture rates on neutron-rich nuclei (A>65) were calculated within the Random Phase Approximation with partial number formalism, including allowed and forbidden transitions. The partial occupation numbers were provided as a…
We propose a new model to calculate stellar electron capture rates for neutron-rich nuclei. These nuclei are encountered in the core-collapse of a massive star. Using the Shell Model Monte Carlo approach, we first calculate the finite…