A comparison of the (p, α) and (t, α) reactions in the shape transitional region near N ≃ 90

A comparison has been made between the (p, α) and (t, α) reactions leading to 147, 149, 151Pm and 153, 155Eu. A strong correlation was observed between the cross sections in the two reaction types except for the results leading into 149Pm. Direct three-nucleon microscopic and cluster transfer reaction calculations and also two-step sequential transfer reaction calculations were made for the (p, α) angular distributions. Several sets of α optical model and bound state parameters were tried. The shape of the predicted angular distributions were found to be determined by the α optical model and bound state parameters. The two-step sequential transfer calculations reproduced the magnitude of the 158Gd(p, α) data within a factor of two for all three parameter sets tried.