Department
Physics
Document Type
Article
Publication Date
6-2017
Embargo Period
7-3-2018
Abstract
We present the first measurement of the Michel parameters ¯η and ξκ in the radiative leptonic decay of the τ lepton using 703 fb−1 of data collected with the Belle detector at the KEKB e +e − collider. The Michel parameters are measured by an unbinned maximum likelihood fit to the kinematic information of e +e − → τ +τ − → (π +π 0ν¯)(l −ννγ¯ ) (l = e or µ). The preliminary values of the measured Michel parameters are ¯η = −2.0 ± 1.5 ± 0.8 and ξκ = 0.6 ± 0.4 ± 0.2, where the first error is statistical and the second is systematic.
Journal Title
Nuclear and Particle Physics Proceedings
Journal ISSN
2405-6014
Volume
287-288
First Page
11
Last Page
14
Digital Object Identifier (DOI)
10.1016/j.nuclphysbps.2017.03.034
Comments
Preprint.