Related papers: A Full $PF$ Shell Model Study of a~=~48 Nuclei
The one-dimensional harmonic oscillator in a box problem is used to introduce the concept of a mixed-mode shell-model scheme. The method combines low-lying ``pure mode'' states of a system to achieve a better description in situations where…
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…
We present recent shell-model calculations of the gamma-decay in sd-pf and pf-shell nuclei. We focus on the M1 part of the dipole strength which was shown to exhibit interesting low-energy effects, in particular a low-energy enhancement…
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 potential-energy surfaces of an extended set of heavy and super-heavy even-even nuclei with $92 \le Z \le 126$ and isospins $40 \le N-Z \le 74$ are evaluated within the recently developed Fourier shape parametrization. Ground-state and…
Studies of the $\gamma$-ray strength functions can reveal useful information concerning underlying nuclear structure. Accumulated experimental data on the strength functions show an enhancement in the low $\gamma$ energy region. We have…
The structure of weakly bound and unbound nuclei close to particle drip lines is one of the major science drivers of nuclear physics. A comprehensive understanding of these systems goes beyond the traditional configuration interactions…
Gamow-Teller transitions in nuclei tell us that the nucleon's axial charge $g_A^{(3)}$ is quenched in large nuclei by about 20%. This result tells us that the spin structure of the nucleon is modified in nuclei and disfavours models of the…
The spectral statistics of low--lying states of several $fp$ shell nuclei are studied with realistic shell--model calculations. For Ca isotopes, we find significant deviations from the predictions of the random--matrix theory which suggest…
The advent of nucleon-nucleon potentials derived from chiral perturbation theory, as well as the so-called V-low-k approach to the renormalization of the strong short-range repulsion contained in the potentials, have brought renewed…
We investigate the effect of pairing correlations on the computed Gamow-Teller (GT) strength distributions and corresponding $\beta$-decay half-lives. The calculations are performed for a total of 47 sd-shell nuclei, for $20 < A < 30$,…
Two-particle two-hole (2p2h) effect on the Gamow-Teller (GT) transition for neutron-rich nuclei is studied by the second Tamm-Dancoff approximation (STDA) with the Skyrme interaction. Unstable $^{24}$O and $^{34}$Si, and stable $^{48}$Ca…
We study neutrinoless double-beta decay in an effective field theory (EFT) for heavy nuclei, which are treated as a spherical core coupled to additional neutrons and/or protons. Since the low-energy constants of the EFT cannot be fitted to…
Gamow-Teller (GT) transitions play an important and consequential role in many astrophysical phenomena. These include, but are not limited to, electron and positron capture rates which determine the fate of massive stars and play an…
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…
Precision measurements of $\beta$-decay observables offer the possibility to search for deviations from the Standard Model. A possible discovery of such deviations requires accompanying first-principles calculations. Here we compute the…
A new method has been proposed to determine the strength of the isoscalar proton-neutron pairing interaction applicable to many nuclei. The principle is the equivalence between the double charge change and the double transfer of…
The Gamow-Teller strength (GT) distributions and electron capture rates on 55Co and 56Ni have been calculated using the proton-neutron quasiparticle random phase approximation theory. We calculate these weak interaction mediated rates over…
The Gamow-Teller(GT) states are investigated in relativistic models. The Landau-Migdal(LM) parameter is introduced in the Lagrangian as a contact term with the pseudo-vector coupling. In the relativistic model the total GT strength in the…
For natural parity states of several odd-A nuclei a comparison of shell model calculations in the full pf configuration space with the Nilsson diagram and particle-rotor predictions shows that prolate strong coupling applies at low…