Abstract
Experimental studies of neutron decay, , exhibit two anomalies. The first is a 8.6(2.1) s, roughly difference between the average beam measured neutron lifetime, , and the more precise average trapped ultracold neutron determination, . The second is a difference between the pre2002 average axial coupling, , as measured in neutron decay asymmetries , and the more recent, post2002, average , where, following the UCNA Collaboration division, experiments are classified by the date of their most recent result. In this Letter, we correlate those and values using a (slightly) updated relation . Consistency with that relation and better precision suggest and as preferred values for those parameters. Comparisons of with recent lattice QCD and muonic hydrogen capture results are made. A general constraint on exotic neutron decay branching ratios, , is discussed and applied to a recently proposed solution to the neutron lifetime puzzle.
- Received 22 February 2018
DOI:https://doi.org/10.1103/PhysRevLett.120.202002
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.
Published by the American Physical Society