The low-energy logarithmic derivative of the $S$ factor for ${}_{}{}^7{}_{}{}^{}\mathrm{Be}(\mathrm{p}, \gamma ){}_{}{}^8{}_{}{}^{}\mathrm{B}$ calculated by Williams and Koonin using only asymptotic wave functions differs from that obtained with a potential model. It is suggested that this is due at least in part to an inappropriate choice of nuclear phase shift in the former calculation.

NUCLEAR REACTIONS ${}_{}{}^7{}_{}{}^{}\mathrm{Be}(\mathrm{p}, \gamma ){}_{}{}^8{}_{}{}^{}\mathrm{B}$, $E<\mathrm{}100\mathrm{}$ keV, extrapolated $S$.

• Received 3 May 1983

DOI:https://doi.org/10.1103/PhysRevC.28.1407