The Nab collaboration will perform a precise measurement of 'a', the electron-neutrino correlation parameter, and 'b', the Fierz interference term in neutron beta decay, in the Fundamental Neutron Physics Beamline at the SNS, using a novel electric/magnetic field spectrometer and detector design. The experiment is aiming at the 10^{-3} accuracy level in (Delta a)/a, and will provide an independent measurement of lambda = G_A/G_V, the ratio of axial-vector to vector coupling constants of the nucleon. Nab also plans to perform the first ever measurement of 'b' in neutron decay, which will provide an independent limit on the tensor weak coupling.
@article{arxiv.0810.0251,
title = {Nab: Measurement Principles, Apparatus and Uncertainties},
author = {D. Pocanic and R. Alarcon and L. P. Alonzi and S. Baessler and S. Balascuta and J. D. Bowman and M. A. Bychkov and J. Byrne and J. R. Calarco and V. Cianciolo and C. Crawford and E. Frlez and M. T. Gericke and G. L. Greene and R. K. Grzywacz and V. Gudkov and F. W. Hersman and A. Klein and J. Martin and S. A. Page and A. Palladino and S. I. Penttila and K. P. Rykaczewski and W. S. Wilburn and A. R. Young and G. R. Young},
journal= {arXiv preprint arXiv:0810.0251},
year = {2014}
}
Comments
12 pages, 6 figures, 1 table, talk presented at the International Workshop on Particle Physics with Slow Neutrons, Grenoble, 29-31 May 2008; to appear in Nucl. Instrum. Meth. in Physics Research A