Systematic study on α-decay half-lives of Bi isotopes

Systematic calculations on a-decay half-lives of Bi isotopes are performed by using the generalized liquid drop model (GLDM) and several sets of Royer's analytic formulas. In calculations, the a transitions include the ones of (i) ground state (g.s.) to g.s., (ii) g.s. to isomeric state (i.s.), (iii) i.s. to g.s., (iv) i.s. to i.s. According to the comparison between the calculated half-lives and the experimental data, it is found that the experimental half-lives are reproduced well by the GLDM with the cluster-like mode. This indicates that the nuclear structure details play important roles in the a-decay half-lives. In addition, it is found that the experimental half-lives are not reproduced well by these analytic formulas because the parameters are obtained by fitting the experimental half-lives of g.s. to g.s. transitions. To give better predictions on a-decay half-lives, the parameters in these formulas should be refitted by including the experimental a-transition of (ii)-(iv) mentioned above.