Weak proton capture on 3He
Abstract
The astrophysical S factor for the proton weak capture on 3He is calculated with correlated-hyperspherical-harmonics bound and continuum wave functions corresponding to realistic Hamiltonians consisting of the Argonne v14 or Argonne v18 two-nucleon and Urbana-VIII or Urbana-IX three-nucleon interactions. The nuclear weak charge and current operators have vector and axial-vector components that include one- and many-body terms. All possible multipole transitions connecting any of the p-3He S- and P-wave channels to the 4He bound state are considered. The S factor at a p-3He center-of-mass energy of 10 keV, close to the Gamow-peak energy, is predicted to be 10.1×10-20 keV b with the AV18/UIX Hamiltonian, a factor of ≃4.5 larger than the value adopted in the standard solar model. The P-wave transitions are found to be important, contributing about 40% of the calculated S factor. The energy dependence is rather weak: the AV18/UIX zero-energy S factor is 9.64×10^-20 keV b, only 5% smaller than the 10 keV result quoted above. The model dependence is also found to be weak: the zero-energy S factor is calculated to be 10.2×10^-20 keV b with the older AV14/UVIII model, only 6% larger than the AV18/UIX result. Our best estimate for the S factor at 10 keV is therefore (10.1±0.6)×10^-20 keV b, when the theoretical uncertainty due to the model dependence is included. This value for the calculated S factor is not as large as determined in fits to the Super-Kamiokande data in which the hep flux normalization is free. However, the precise calculation of the S factor and the consequent absolute prediction for the hep neutrino flux will allow much greater discrimination among proposed solar neutrino oscillation solutions.
Additional Information
©2000 The American Physical Society Received 5 June 2000; published 4 December 2000 The authors wish to thank V.R. Pandharipande, D.O. Riska, P. Vogel, and R.B. Wiringa for useful discussions, and J. Carlson for a critical reading of the manuscript. M.V. and R.S. acknowledge partial financial support of NATO through the Collaborative Research Grant No. 930741. The support of the U.S. Department of Energy under Contract No. DE-AC05-84ER40150 is gratefully acknowledged by L.E.M. and R.S. Finally, some of the calculations were made possible by grants of computing time from the National Energy Research Supercomputer Center in Livermore.Files
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Additional details
- Eprint ID
- 5365
- Resolver ID
- CaltechAUTHORS:MARprc01
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2006-10-13Created from EPrint's datestamp field
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2021-11-08Created from EPrint's last_modified field