Differential cross section angular distributions for the ${}_{}{}^{6,7}{}_{}{}^{}\mathrm{Li}$(p,n${)}^{6,7}$Be reactions have been measured at energies between 60 and 200 MeV. The experimental angular distributions are analyzed using a microscopic distorted wave impulse approximation. The results of self-consistent microscopic distorted wave calculations based on a complete set of weak and electromagnetic data for the mass 6 and 7 systems are also presented. Total observed Gamow-Teller strength up to about 40 MeV excitation energy is reported. Energy dependence of the στ and τ effective interaction terms are presented up to 200 MeV. The measured (p,n) cross sections for the ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$ (g.s.) and ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$ (0.43 MeV) transitions are used to obtain the branching ratio of the ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$ (g.s.) decay to the g.s. and 0.478 MeV states in ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$. Zero degree polarization transfer (${\mathit{D}}_{\mathit{N}\mathit{N}}$) data at ${\mathit{E}}_{\mathit{p}}$=80, 120, 160, and 200 MeV are reported for the ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$(p,n${)}^6$Be (g.s.) and for the ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$(p,n${)}^7$Be (g.s.+0.43 MeV) reactions. Energy dependence of total and zero degree differential cross section for the ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$(p,n${)}^7$Be (g.s.+0.43 MeV) transitions are reported. Finally a comparison is presented for the (n,p), (p,p’), and (p,n) reaction in ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ populating isospin triplets.

• Received 20 November 1989

DOI:https://doi.org/10.1103/PhysRevC.41.1920