Madhubrata Bhattacharya

Microscopic calculation of half lives of spherical proton emitters

Abstract Half life values for proton radioactivity in nuclei have been calculated in the WKB approximation. The microscopic proton–nucleus potential has been obtained by folding the densities of daughter nuclei with two microscopic NN interactions, DDM3Y and JLM. The densities have been obtained in the Relativistic Mean Field approach in the spherical approximation using the force FSU Gold. No substantial modification of results has been observed if other common forces are employed. The calculated results for the decays from the ground state or the low-lying excited states in almost all the nuclei agree well with experimental measurements. Reasons for large deviations in a few cases have been discussed. Results in 109 I and 112,113 Cs show that the effect of deformation is small contrary to earlier calculations. Predictions for possible proton radioactivity have been made in two nuclei, 93 Ag and 97 In.

Cluster decay in very heavy nuclei in a relativistic mean field model

Exotic cluster decay of very heavy nuclei was studied in the microscopic Super-Asymmetric Fission Model. The Relativistic Mean Field model with the force FSU Gold was employed to obtain the densities of the cluster and the daughter nuclei. The microscopic nuclear interaction DDM3Y1, which has an exponential density dependence, and the Coulomb interaction were used in the double folding model to obtain the potential between the cluster and the daughter. Half-life values were calculated in the WKB approximation and the spectroscopic factors were extracted. The latter values are seen to have a simple dependence of the mass of the cluster as has been observed earlier. Predictions were made for some possible decays.

α-decay lifetime in superheavy nuclei with A > 282

Nuclei with

Spectroscopic factors for alpha decay in the N(p)N(n) scheme

Ag282

Helium nuclei around the neutron drip line

have been studied in the relativistic mean field approach using the force FSU Gold and a zero range pairing interaction. The Euler-Lagrange equations have been solved in the coordinate space. The \ensuremath{\alpha}-nucleus potential has been constructed with the density-dependent M3Y interaction (DDM3Y1), which has an exponential density dependence, in the double folding model using the nucleon densities in the daughter nucleus and the \ensuremath{\alpha} particle. Half-lives of \ensuremath{\alpha} decay have been calculated for tunneling of the \ensuremath{\alpha} particle through the potential barrier in the WKB approximation and assuming a constant preformation probability. The resulting values agree well with experimental measurements.

Correction to Relativistic Mean Field binding energy and NpNn scheme

Abstract Lifetime values for alpha decay in even–even nuclei with Z = 84 – 98 and N = 128 – 152 have been calculated in the superasymmetric fission model. The interaction between the alpha particle and the daughter nucleus has been formed in the double folding approach using a density dependent NN interaction. The densities have been obtained using the Relativistic Mean Field formalism. The spectroscopic factors for the decays have been deduced and are shown to vary smoothly as a function of effective numbers of valence nucleons, N p and N n chosen with a suitable core. The implication of such a smooth behaviour has been discussed.

Massive neutron stars with a hyperonic core: A case study with the IUFSU relativistic effective interaction

Neutron rich He nuclei have been investigated using relativistic mean field approach in co-ordinate space. Elastic partial scattering cross sections for proton scattering in inverse kinematics have been calculated using the theoretically obtained density for

Role of pairing interaction in neutron rich odd and even Zr nuclei

^{6,8}

Relativistic mean field calculations in neutron-rich nuclei

He and compared with experiment. The energies of the low-lying resonance states in the neutron unstable nuclei

Neutron drip line in odd and even mass calcium and nickel nuclei

^{5,7}