(p,n) reactions on C14 and N14 and the effective nucleon-nucleon interaction

Differential cross sections for the /sup 14/N(p,n)/sup 14/O(g.s.) reaction have been measured at E/sub p/ = 35.2 MeV with a gas-cell target. Differential cross sections for (p,n) reactions on /sup 14/C leading to the first three levels in /sup 14/N have been obtained with an isotopically-enriched graphite target for bombarding energies of 25.7, 35, and 45 MeV. The /sup 14/C(p,n)/sup 14/N(2.31 MeV) cross sections have been analyzed with Lane-model distorted-wave Born approximation calculations to extract energy-dependent well depths for the isovector part of the optical potential. These isovector well depths have been combined with a set of isoscalar optical-potential parameters derived from elastic proton scattering on /sup 14/N. The resulting optical potential has been used in microscopic distorted-wave Born approximation analyses of the (p,n) differential cross sections. Strengths for the isovector central V/sub tau/ and V/sub sigmatau/ and isovector tensor V/sub T/tau components of the effective interaction have been extracted. A comparison of the isospin-symmetric /sup 14/C(p,n)/sup 14/N(g.s.), /sup 14/N(p,n)/sup 14/O(g.s.), and /sup 14/N(p,p')/sup 14/N(2.31 MeV) reactions has been made, and unexpected differences among the angular distributions are found.