The Solar $hep$ Processes in Effective Field Theory

Abstract

By combining effective field theory with the standard nuclear physics approach (SNPA) we obtain a high-precision estimate of the $S$ factor for the solar $hep$ process. The accurate wave functions available in SNPA are used to evaluate the nuclear matrix elements for the transition operators that result from chiral perturbation theory (ChPT). All the contributions up to \nlo3 in ChPT are included. The resulting parameter-free, error-controlled prediction is: $S(hep)=(8.6 \pm 1.3)\times 10^{-20}$ keV-b.