Measurement of the neutrino asymmetry in the beta decay of laser-cooled, polarized K-37
Academic Article
Overview
Research
Identity
Additional Document Info
Other
View All
Overview
abstract
A measurement of the neutrino asymmetry is presented which represents the first search for new physics using polarized radioactive atoms initially cooled and confined in a magneto-optical trap. Optical pumping and photoionization techniques are used to generate and measure, in situ, a highly spin-polarized (96.5 (0.8) %) sample of the short-lived +-emitter 37K. The angular distribution of neutrinos from this polarized decay, inferred from the daughter recoil asymmetry, is used to search for a hypothetical V + A current in the weak interaction. We find the asymmetry parameter to be B = - 0.755 0.020 (stat) 0.013 (syst), in agreement with the standard model's purely V - A interaction. 2007 Elsevier B.V. All rights reserved.