KeV Astrophysics with GeV Beams; Blazing a New Trail on the Summit of Nuclear Astrophysics

Abstract

GeV beams of light ions and electrons are used for creating a high flux of real and virtual photons, with which some problems in Nuclear Astrophysics are studied. GeV 8B beams are used to study the Coulomb dissociation of 8B and thus the 7Be(p,gamma)8B reaction. This reaction is one of the major source of uncertainties in estimating the 8B solar neutrino flux and a critical input for calculating the 8B Solar neutrino flux. The Coulomb dissociation of 8B appears to provide a viable method for measuring the 7Be(p,gamma)8B reaction rate, with a weighted average of the RIKEN1, RIKEN2, GSI1 and MSU published results of S17(0) = 18.9 +/- 1.0 eV-b. This result however does not include a theoretical error estimated to be +/- 10 %. GeV electron beams on the other hand, are used to create a high flux of real and virtual photons at TUNL-HIGS and MIT-Bates, respectively, and we discuss two new proposals to study the 12C(alpha,gamma)16O reaction with real and virtual photons. The 12C(alpha,gamma)16O reaction is essential for understanding Type II and Type Ia supernova. It is concluded that virtual and real photons produced by GeV light ions and electron beams are useful for studying some problems in Nuclear Astrophysics.