Cross sections at 0° for the pure Fermi ($0^{+}$, 2.31, MeV) and Gamow-Teller ($1^{+}$, 3.95 MeV) states in the ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$(p,n${)}^{14}$N reaction have been measured at ${\mathit{E}}_{\mathit{p}}$=494, 644, and 795 MeV using the LAMPF neutron time-of-flight facility with a new 617-m neutron flight path. The measured cross sections per unit transition strength, σ^, provide a measure of the isovector spin-flip and non-spin-flip central components of the effective nucleon-nucleon interaction. Cross sections and the ratio ${\mathit{R}}^2$=σ${\mathrm{^}}_{\mathrm{GT}}$/σ${\mathrm{^}}_{\mathrm{F}}$ are compared to lower-energy measurements and to calculations using a free NN t matrix.

• Received 25 May 1990

DOI:https://doi.org/10.1103/PhysRevLett.65.551