αdecay of nuclei in the range67⩽Z⩽91from the ground state and isomeric state

Abstract

The Coulomb and proximity potential model for deformed nuclei (CPPMDN) is used to study the favored and unfavored $\ensuremath{\alpha}$ decay of nuclei in the range $67$ \ensuremath{\leqslant} $Z$ \ensuremath{\leqslant} $91$ from both the ground state (g.s.) and isomeric state (i.s.). The computed half-lives are in good agreement with experimental data. The standard deviation of half-life is found to be 0.44. Geiger-Nuttall (GN) plots for various parent isotopes are studied. It is found that all four types of transitions (g.s.\ensuremath{\rightarrow}g.s., g.s.\ensuremath{\rightarrow}i.s., i.s.\ensuremath{\rightarrow}g.s., i.s.\ensuremath{\rightarrow}i.s.) lie on a straight line. The isomeric state $\ensuremath{\alpha}$ decay shows a behavior similar to that of the ground state and the nuclear structure of the isomeric states imitates that of the ground states. Some predictions are done for $\ensuremath{\alpha}$ transition from both ground and isomeric states, which will be useful for future experiments.