Related papers: Nuclear Structure Features of Gamow-Teller Excitat…
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…
The general phenomenon of shell structure in atomic nuclei has been understood since the pioneering work of Goeppert-Mayer, Haxel, Jensen and Suess.They realized that the experimental evidence for nuclear magic numbers could be explained by…
We investigated the Gamow-Teller (GT) strength distribution, especially the quenching with respect to the GT sum rule, and the enhancement of the pionic responses in the quasielasic scattering region, in the same theoretical framework. That…
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…
The proportionality between single charge-exchange reaction cross sections in the forward direction as found, for example from $(p,n)$ and $(^3$He,$t)$ and from $(n,p)$ and $(d,^2$He) reactions, and the Gamow-Teller (GT) strength into the…
We show that the dominant Gamow-Teller part, $M^{0\nu}_{GT}$, of the nuclear matrix element governing the neutrinoless $\beta\beta$ decay is related to the matrix element $M^{2\nu}_{cl}$ governing the allowed two-neutrino $\beta\beta$…
Beta-decay properties of neutron-rich Zr and Mo isotopes are investigated within a microscopic theoretical approach based on the proton-neutron quasiparticle random-phase approximation. The underlying mean field is described…
Recently it has been shown that pseudospin symmetry has its origins in a relativistic symmetry of the Dirac Hamiltonian. Using this symmetry we relate single - nucleon relativistic magnetic moments of states in a pseudospin doublet to the…
The description of nuclear reactions induced by supernova neutrinos has witnessed significant progress during the recent years. At the energies and momentum transfers relevant for supernova neutrinos neutrino-nucleus cross sections are…
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…
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…
Gamow-Teller (GT) strength distributions of Mg isotopes are investigated within a framework of the deformed quasi-particle random phase approximation(DQRPA). We found that the N=20 shell closure in $^{28 \sim 34}$Mg was broken by the…
We discuss some special aspects of the nuclear many-body problem related to isospin transfer. The major quantity of interest is the in-medium propagator of a particle-hole configuration of the proton-neutron character, which determines the…
The basic version of the semi-microscopic particle-hole dispersive optical model is implemented to describe main properties of the Gamow-Teller and charge-exchange giant spin-monopole resonances in medium-heavy closed-shell parent nuclei.…
Full one-loop radiative corrections are calculated for low energy neutrino-nucleon quasi-elastic scattering, $\bar \nu_{e}+p \longrightarrow e^{+} + n$, which involves both Fermi and Gamow-Teller transitions, in the static limit of…
For the embedded Gaussian orthogonal ensemble (EGOE) of random matrices, the strength sums generated by a transition operator acting on an eigenstate vary with the excitation energy as the ratio of two Gaussians. This general result is…
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…
Transition probabilities of the ground-state bands in $\gamma$-soft nuclei are studied for the first time using the triaxial projected shell model approach. It is observed that the angular-momentum dependence of the transition quadrupole…
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…
The spin-orbit splittings in the spectra of nuclei with mass numbers 5, 15 and 17 are studied within the framework of shell-model configuration mixing calculations including 2$\hbar \omega$ excitations. The contributions of the two-body…