Differential cross sections have been measured near 0° for the dominant channels in the mirror reaction ${}^{13}$C${(}^{13}$N${,}^{13}$C${)}^{13}$N at $E/A=57\mathrm{}$ and 105 MeV. The cross sections of the peaks in the excitation spectrum are discussed in terms of Gamow-Teller and Fermi transition strength. The cross section per unit Gamow-Teller strength is found to be enhanced relative to that for unit Fermi strength when compared with previous results from $(p,n)$ reactions. The present work represents the first use of a mirror-symmetric projectile and target system in a charge-exchange reaction as well as the first application of the developing radioactive nuclear beam field to this area.

• Received 3 August 1995

DOI:https://doi.org/10.1103/PhysRevLett.76.26