Gamow-teller β+ decays and strength functions of (n,p) transitions in spherical nuclei

Abstract

Abstract The effect of the particle-particle interaction on the Gamow-Teller β + decay and strength functions of (n, p) transitions is studied. The integrated log ft values for the GT decays of 152 Yb, 152,150 Er, 146,148 Dy and 96 Pd are calculated in the RPA with separable particle-hole and particleparticle interactions. A good description of log Ft is obtained with the constants χ(s01) 1 = −23 A MeV and G 01 1 = 7.5/ AMeV at ¦g A /g v ¦=1 and G 01 1 = 7.9/ AMeV at| g A / g v v | = 1.25. experimental data on β + decays of nuclei far from stability one cannot conclude that the weak axial-vector constant g A is strongly renormalised in nuclei. The particle-particle interaction is shown to influence strongly the total strength S + of (n, p) transitions by diminishing it (1.5–3.0) times. For the reaction 54 Fe(n, p) 54 at forward angles the calculated value S + = 4.2 is in agreement with the experimental one.