Tensor analyzing powers and energy dependence of theLi7+O16interaction

Abstract

The differential cross section angular distribution and the analyzing powers ${}^{T}{T}_{10},{}^{T}{T}_{20}$, for $^{7}\mathrm{Li}$+$^{16}\mathrm{O}$ elastic scattering were measured at ${E}_{\mathrm{lab}}({}^{7}\stackrel{\ensuremath{\rightarrow}}{\mathrm{Li}}$) = 42 MeV. These and previously published $^{7}\mathrm{Li}$+$^{16}\mathrm{O}$ scattering data measured at ${E}_{c.m.}$ = 6.26\ensuremath{-}34.78 MeV were analyzed with the optical model and coupled-reaction channels (CRC) methods to determine the energy dependence of the parameters of the scattering potential. It was found that the optical model potentials are energy independent for $^{7}\mathrm{Li}$ laboratory bombarding energies above 28 MeV, except for a slight decrease in the real potential strength as the bombarding energy increases. The calculations presented show that the tensor analyzing power ${}^{T}{T}_{20}$ arises from a coherent combination of contributions from the ground-state reorientation and central scattering potential. The energy-dependent CRC potentials were shown to describe the data for the $^{16}\mathrm{O}$($^{7}\mathrm{Li}$,$t$)$^{20}\mathrm{Ne}$ reaction.