Fine structure inαdecay of even-even nuclei using a finite-range nucleon-nucleon interaction

Abstract

A systematic study on $\ensuremath{\alpha}$-decay fine structure is presented for even-even nuclei in the range $78\ensuremath{\le}Z\ensuremath{\le}102$. The penetration probability is obtained from the WKB approximation in combination with the Bohr-Sommerfeld quantization condition. The potential barrier is numerically constructed in the well-established double-folding model for both Coulomb and nuclear potentials. A realistic M3Y interaction, based on the $G$-matrix elements of the Paris $NN$ potential, has been used in the folding calculation. The local approximation for the nondiagonal one-body density matrix in the calculation of the exchange potential was included by using the harmonic oscillator representation of the nondiagonal density matrix of the $\ensuremath{\alpha}$ particle. The computed partial half-lives and branching ratios are compared with the recent experimental data and they are in good agreement.