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Related papers: Electron Capture Rates of Mid-fp Shell Nuclei for …

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The Gamow-Teller strength distribution function, B(GT), for the odd Z parent $^{51}$V, $N-Z$ =5, up to 30 MeV of excitation energy in the daughter $^{51}$Ti is calculated in the domain of proton-neutron Quasiparticle Random Phase…

Nuclear Theory · Physics 2015-06-22 Muneeb-Ur Rahman , Jameel-Un Nabi

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…

Nuclear Theory · Physics 2021-07-07 Karlheinz Langanke , Gabriel Martínez-Pinedo , Remco Zegers

Isotopes of nickel play a key role during the silicon burning phase up to the presupernova phase of massive stars. Electron capture rates on these nickel isotopes are also important during the phase of core contraction. I present here the…

Nuclear Theory · Physics 2015-06-22 Jameel-Un Nabi

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…

Nuclear Theory · Physics 2016-02-22 Muneeb-Ur Rahman , Jameel-Un Nabi

This paper reports on the microscopic calculation of ground and excited states Gamow-Teller (GT) strength distributions, both in the electron capture and electron decay direction, for $^{54,55,56}$Fe. The associated electron and positron…

Nuclear Theory · Physics 2012-03-22 Jameel-Un Nabi

We present calculation of electron capture cross sections (ECC), in the limit of zero momentum transfer, using the pn QRPA model in stellar matter. Towards this aim we make use of our recently introduced recipe for estimation of nuclear…

Nuclear Theory · Physics 2025-03-11 Jameel-Un Nabi , Muhammad Riaz

In a recent study by Cole et al., it was concluded that QRPA calculations show larger deviations and overestimate the total experimental Gamow-Teller (GT) strength. It was also concluded that QRPA calculated electron capture rates exhibit…

Nuclear Theory · Physics 2025-04-28 Muhammad Majid , Jameel-Un Nabi , Muhammad Riaz

Electron capture and beta decay play important roles in the evolution of pre-supernovae stars and their eventual core collapse. These rates are normally predicted through shell-model calculations. Experimentally determined strength…

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…

Nuclear Theory · Physics 2009-10-31 E. Caurier , K. Langanke , G. Martinez-Pinedo , F. Nowacki

Background: The strength of electron capture for medium mass nuclei has a significant effect on the evolution of supernovae. There is insufficient knowledge of these strengths and very little data for important radioactive nuclei. Purpose:…

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…

Nuclear Theory · Physics 2020-02-18 Alan A. Dzhioev , K. Langanke , G. Martínez-Pinedo , A. I. Vdovin , Ch. Stoyanov

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}…

Nuclear Theory · Physics 2011-05-05 K. Langanke , G. Martinez-Pinedo

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…

Nuclear Experiment · Physics 2016-10-25 G. W. Hitt , S. Gupta , R. G. T. Zegers , R. Titus , C. Sullivan , B. A. Brown , A. L. Cole , S. Shams

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…

Nuclear Theory · Physics 2015-06-26 J. M. Sampaio , K. Langanke , G. Martinez-Pinedo , E. Kolbe , D. J. Dean

Capture of electrons by nuclei is an important process in stellar environments where excited nuclear states are thermally populated. However, accurate treatment for excited configurations in electron capture (EC) rates has been an unsolved…

Nuclear Theory · Physics 2022-01-05 Long-Jun Wang , Liang Tan , Zhipan Li , Bingshui Gao , Yang Sun

In the late stages of stellar core-collapse, prior to core bounce, electron captures on medium-heavy nuclei drive deleptonization and simulations require the use of accurate reaction rates. Nuclei with neutron number near $N=50$, just above…

Electron captures on nuclei play an important role in the dynamics of the collapsing core of a massive star that leads to a supernova explosion. Recent calculations of these capture rates were based on microscopic models which account for…

Nuclear Theory · Physics 2010-11-23 A. Juodagalvis , K. Langanke , W. R. Hix , G. Martínez-Pinedo , J. M. Sampaio

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…

Cobalt-55 is not only present in abundance in presupernova phase but is also advocated to play a decisive role in the core collapse of massive stars. The spectroscopy of electron capture and emitted neutrinos yields useful information on…

Nuclear Theory · Physics 2014-08-18 Jameel-Un Nabi , Muneeb-Ur Rahman , Muhammad Sajjad

Gamow-Teller (GT) transitions play a preeminent role in the collapse of stellar core in the stages leading to a Type-II supernova. The B(GT) strength distributions for ground and excited states of $^{57}$Zn are calculated in the domain of…

Nuclear Theory · Physics 2012-03-22 Jameel-Un Nabi , Muneeb-Ur Rahman