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arXiv · 0710.5197

Search for the second forbidden beta decay of 8B to the ground state of 8Be

M. K. Bacrania·N. M. Boyd·R. G. H. Robertson·D. W. Storm
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Abstract

A significant decay branch of 8B to the ground state of 8Be would extend the solar neutrino spectrum to higher energies than anticipated in the standard solar models. These high-energy neutrinos would affect current neutrino oscillation results and also would be a background to measurements of the hep process. We have measured the delayed alpha particles from the decay of 8B, with the goal of observing the two 46-keV alpha particles arising from the ground-state decay. The 8B was produced using an in-flight radioactive beam technique. It was implanted in a silicon PIN-diode detector that was capable of identifying the alpha-particles from the 8Be ground state. From this measurement we find an upper limit (at 90% confidence level) of 7.3 x 10^{-5} for the branching ratio to the ground state. In addition to describing this measurement, we present a theoretical calculation for this branching ratio.

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M. K. Bacrania, N. M. Boyd, R. G. H. Robertson, D. W. Storm. 2007-12-07. Search for the second forbidden beta decay of 8B to the ground state of 8Be. https://doi.org/10.1103/physrevc.76.055806

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