Proton widths of the low-lying 16 F states from the 15 N( 7 Li, 6 Li) 16 N reaction
All the ${}^{16}\mathrm{F}$ levels are unbound by proton emission. To date the four low-lying ${}^{16}\mathrm{F}$ levels below 1 MeV have been experimentally identified with well established spin-parity values and excitation energies with an accuracy of 4 -- 6 keV. However, there are still considerable discrepancies in their level widths. The present work aims to explore these level widths through an independent method. The angular distributions of the ${}^{15}N$(${}^{7}\mathrm{Li}$, ${}^{6}\mathrm{Li}$)${}^{16}\mathrm{N}$ reaction leading to the first four states in ${}^{16}\mathrm{N}$ were measured using a high-precision Q3D magnetic spectrograph. The neutron spectroscopic factors and the asymptotic normalization coefficients for these states in ${}^{16}\mathrm{N}$ were then derived based on distorted wave Born approximation analysis. The proton widths of the four low-lying resonant states in ${}^{16}\mathrm{F}$ were obtained according to charge symmetry of strong interaction.