Abstract
Angular distributions have been measured for → transitions with the CB) reaction on targets of ,Mg, ,Ni, and and with the CN) reaction on targets of and . The bombarding energy was E/A=70 MeV, and small-angle data were obtained. A comparison of the cross sections measured for the CB) reaction with the results of distorted-wave-approximation calculations indicates that → transitions are predominantly one step at E/A=70 MeV. The calculated cross sections are generally in good agreement (to within 40% in magnitude) with the measured cross sections, and the angular distributions are well described quantitatively in many cases. A correlation between cross sections and known Gamow-Teller (GT) strengths B(GT) for the corresponding transitions has been found. This correlation, which is weakly dependent on the target mass, establishes a calibration for the reactions. It is used to determine B(GT) values of astrophysical interest for two low-lying levels in from the cross sections measured for the CNMn reaction. The results are compared with two shell-model calculations performed to obtain B(GT) for Mn transitions and with another calculation from the literature. Computational tests were performed to evaluate (a) the contribution to the cross sections of terms not present in nucleon-induced charge-exchange reactions and (b) the extent to which the cross sections provide a measure of GT strength.
- Received 11 February 1991
DOI:https://doi.org/10.1103/PhysRevC.44.398
©1991 American Physical Society