R. Sahu

Deformed shell model calculations of half lives for {beta}{sup +}/EC decay and 2{nu} {beta}{sup +}{beta}{sup +}/{beta}{sup +}EC/ECEC decay in medium-heavy N{approx}Z nuclei

The {beta}{sup +}/EC half-lives of medium heavy N{approx}Z nuclei with mass number A{approx}64-80 are calculated within the deformed shell model (DSM) based on Hartree-Fock states by employing a modified Kuo interaction in ({sup 2}p{sub 3/2},{sup 1}f{sub 5/2},{sup 2}p{sub 1/2},{sup 1}g{sub 9/2}) space. The DSM model has been quite successful in predicting many spectroscopic properties of N{approx}Z medium heavy nuclei with A{approx}64-80. The calculated {beta}{sup +}/EC half-lives, for prolate and oblate shapes, compare well with the predictions of the calculations with Skyrme force by Sarriguren et al. Going further, following recent searches, half-lives for 2{nu} {beta}{sup +}{beta}{sup +}/{beta}{sup +}EC/ECEC decay for the nucleus {sup 78}Kr are calculated using DSM and the results compare well with QRPA predictions.

Equation of state of supernova matter

The equation of state (EOS) of dense supernova matter composed of protons, neutrons, and relativistic electrons is calculated within finite temperature Brueckner Goldstone approach with effective two-body Sussex interaction and compared with asymmetric nuclear matter. Thermal effect on the EOS is studied at temperature 5, 7, and 10 MeV. The EOS of supernova matter is found to be stiffer than the corresponding asymmetric nuclear matter equation of state as expected. Single particle properties like distribution functions and chemical potentials of proton, neutron, and electron are discussed for various values of electron fractions, densities, and temperatures. Distribution function is found to depend on Fermi kinetic energy of respective particles as well as on thermal energy. Chemical potential depends on number density of particles and temperature. It is also seen that the EOS for symmetric nuclear matter at low temperature has same order of magnitude with the recently extracted experimental values within the density range 0.35-0.56 fm{sup -3}.