Positron polarization in the decay of polarized N-12: a precision test of the Standard Model
Thomas, E Prieels, R Allet, M Bodek, K Camps, J Deutsch, J Gimeno-Nogues, F Govaerts, J Lang, J Naviliat-Cuncic, O Pepe, I Quin, P Severijns, Natalis Sromicki, J #
Elsevier science bv
Nuclear Physics A vol:694 issue:3-4 pages:559-589
The longitudinal polarization of positrons emitted along and opposite to the nuclear spin direction has been measured in the decay of polarized N-12. The results are consistent with the Standard Model prediction. In manifest left-right symmetric models this measurement provides a lower bound of 310 GeV/c(2) at 90% CL on the mass of a possible right-handed gauge boson contributing to the electroweak interaction. In generalized versions of this model our measurement provides constraints complementary to those set by high-energy experiments. (C) 2001 Elsevier Science B.V. All rights reserved.