High energy solar neutrinos and p-wave contributions to ^3He(p,\nue^+)^4He

Abstract

High energy solar neutrinos can come from the hep reaction ^3He(p,\nue^+)^4He with a large end point energy of 18.8 MeV. Understanding the hep reaction may be important for interpreting solar neutrino spectra. We calculate the contribution of the axial charge transition ${}^3{P}_0{\to }^1{S}_0$ to the hep thermonuclear S factor using a one-body reaction model involving a nucleon moving in optical potentials. Our result is comparable to or larger than previous calculations of the s-wave Gamow Teller contribution. This indicates that the hep reaction may have p-wave strength leading to an enhancement of the S factor.

Comments: 4 pages, 1 ps figure, very minor changes, Phys. Rev. C in press