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Title: Search for right-handed currents in muon decay

Thesis/Dissertation ·
OSTI ID:6838252

Limits are reported on charged right-handed currents, based on precise measurement of the endpoint e/sup +/ spectrum in ..mu../sup +/ decay. Highly polarized ..mu../sup +/ from the TRIUMF surface muon beam were stopped in high purity metal foils and liquid He targets selected to minimize depolarization effects. Decay e/sup +/ emitted within 160 mrad of the beam direction were momentum-analyzed to 0.15%. Muons were stopped within either a spin-precessing transverse field (70-G or 110-G) or a spin-holding longitudinal field (0.3T or 1.1-T). Data collected with the spin-precessing field were used for the momentum calibration of the spectrometer. The spin-held data were used to measure the relative e/sup +/ rate at the endpoint. For the model with manifest left-right symmetry and massless neutrinos the results implies 90% confidence limits m(WE/sub 2/) > 432 GeV/c/sup 2/ and -0.050 < delta < 0.035, where W/sub 2/ is the predominantly right-handed bosom and delta is the left-right mixing angle. With the assumption of no left-right mixing an equivalent 90% confidence upper limit of 0.025 is obtained on the absolute value of the ratio of a possible V + A amplitude to the dominant V - A amplitude in muon and pion decays. Limits are also deduced on the nu/sub ..mu..bL/ mass and helicity in ..pi../sup +/ decay, non-(V - A) couplings in helicity projection form, the mass scale of composite leptons, and the branching ratio for ..mu.. ..-->.. e + f where f (familon) is the neutral massless Nambu-Goldstone boson associated with flavor symmetry breaking.

Research Organization:
California Univ., Berkeley (USA)
OSTI ID:
6838252
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English