相关论文: Supernova electron capture rates for 55Co and 56Ni

Electron-capture and $\beta$-decay of nuclei in the core of massive stars play an important role in the stages leading to a type II supernova explosion. Nuclei in the f-p shell are particularly important for these reactions in the post…

We propose a new method to calculate stellar weak-interaction rates. It is based on the Thermo-Field-Dynamics formalism and allows the calculation of the weak-interaction response of nuclei at finite temperatures. The thermal evolution of…

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…

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…

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…

We use the shell model Monte Carlo method to calculate complete 0f1p-shell response functions for Gamow-Teller (GT) operators and obtain the corresponding strength distributions using a Maximum Entropy technique. The approach is validated…

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…

Weak rates in nickel isotopes play an integral role in the dynamics of supernovae. Electron capture and $\beta$-decay of nickel isotopes, dictated by Gamow-Teller transitions, significantly alter the lepton fraction of the stellar matter.…

We show that the presently available data on the Gamow-Teller (GT) strength in mid-fp-shell nuclei are proportional to the product of the numbers of valence protons and neutron holes in the full fp-shell. This observation leads to important…

Direct mass measurements of neutron-deficient nuclides around the $N=50$ shell closure below $^{100}$Sn were performed at the FRS Ion Catcher (FRS-IC) at GSI, Germany. The nuclei were produced by projectile fragmentation of $^{124}$Xe,…

Gamow-Teller (GT) strength distributions (B(GT)) in electron-capture (EC) daughters stemming from the parent ground state are computed with the shell-model in the full pf-shell space, with quasi-particle random-phase approximation (QRPA) in…

We have calculated electron capture rates for neutron-rich $N=50$ nuclei ($^{78}$Ni, $^{82}$Ge, $^{86}$Kr, $^{88}$Sr) within the Thermal QRPA approach at temperatures $T=0$, corresponding to capture on the ground-state, and at $T=10$ GK…

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.…

Electron captures on nuclei play an essential role for the dynamics of several astrophysical objects. The capture rate can be derived in perturbation theory where allowed nuclear transitions (Gamow-Teller transitions) dominate, except at…

A systematic shell model description of the experimental Gamow-Teller transition strength distributions in $^{42}$Ti, $^{46}$Cr, $^{50}$Fe and $^{54}$Ni is presented. These transitions have been recently measured via $\beta$ decay of these…

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…

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…

In Gallium detectors for solar neutrinos, the capture rate due to Gamow-Teller transitions to excited states of 71Ge beyond the neutron emission threshold is usually neglected. We make a model calculation to estimate its effect and find…

Charge-changing transitions, commonly referred to as Gamow-Teller (GT) transitions, and electron capture/$\beta^{+}$-decay strengths for pf-shell nuclei with $T_{z} = - 2$ at proton drip-line have been calculated using the proton-neutron…

The 64-Zn(t,3-He) reaction has been studied using a secondary triton beam of 115 MeV/nucleon to extract the Gamow-Teller transition-strength distribution to 64-Cu. The results were compared with shell-model calculations using the pf-shell…