Physics Commons^™

Precision Measurement Of The Radiative Β Decay Of The Free Neutron, M. J. Bales, R. Alarcon, C. D. Bass, E. J. Beise, H. Breuer, J. Byrne, T. E. Chupp, K. J. Coakley, R. L. Cooper, M. S. Dewey, Susan Gardner, T. R. Gentile, D. He, H. P. Mumm, J. S. Nico, B. O'Neill, A. K. Thompson, F. E. Wietfeldt

Physics and Astronomy Faculty Publications

The standard model predicts that, in addition to a proton, an electron, and an antineutrino, a continuous spectrum of photons is emitted in the β decay of the free neutron. We report on the RDK II experiment which measured the photon spectrum using two different detector arrays. An annular array of bismuth germanium oxide scintillators detected photons from 14 to 782 keV. The spectral shape was consistent with theory, and we determined a branching ratio of 0.00335 ± 0.00005[stat] ± 0.00015[syst]. A second detector array of large area avalanche photodiodes directly detected photons from 0.4 to 14 keV. For this …