Nuclear physics input for solar models
The authors discuss microscopic cluster model descriptions of two solar nuclear reactions, {sup 7}Be(p,{gamma}){sup 8}B, and {sup 3}He({sup 3}He, 2p){sup 4}He. The low-energy reaction cross section of {sup 7}Be(p,{gamma}){sup 8}B, which determines the high-energy solar neutrino flux, is constrained by {sup 7}Be and {sup 8}Be observables. The results show that a small value of the zero-energy cross section is rather unlikely. In {sup 3}He({sup 3}He, 2p){sup 4}He the authors study the effects of a possible virtual state on the cross section. Although, they have found no indication for such a state so far, its existence cannot be ruled out yet. They calculated the {sup 3}He({sup 3}He, 2p){sup 4}He and {sup 3}H({sup 3}H, 2n){sup 4}He cross sections in a continuum-discretized coupled channel approximation, and found a good general agreement with the data.