Measurement of the τ Michel parameters η and ξκ in the radiative leptonic decay τ - → l - ν τ ν l γ

Published

Journal Article

© The Author(s) 2018. We present a measurement of the Michel parameters of the τ lepton, η and ξκ, in the radiative leptonic decay τ - → l - ν τ ν l γ using 711 fb -1 of collision data collected with the Belle detector at the KEKB e + e - collider. The Michel parameters are measured in an unbinned maximum likelihood fit to the kinematic distribution of e + e - → τ + τ - → (π + π 0 ν τ )(l - ν τ ν l γ)(l = e or μ The measured values of the Michel parameters are η = -1.3 ± 1.5 ± 0.8 and ξκ = 0.5 ± 0.4 ± 0.2, where the first error is statistical and the second is systematic. This is the first measurement of these parameters. These results are consistent with the Standard Model predictions within their uncertainties, and constrain the coupling constants of the generalized weak interaction.

Full Text

Duke Authors

Cited Authors

  • Shimizu, N; Aihara, H; Epifanov, D; Adachi, I; Said, SA; Asner, DM; Aulchenko, V; Aushev, T; Ayad, R; Babu, V; Badhrees, I; Bakich, AM; Bansa, V; Barberio, E; Bhardwaj, V; Bhuyan, B; Biswal, J; Bobrov, A; Bozek, A; Bračko, M; Browder, TE; Červenkov, D; Chang, MC; Chang, P; Chekelian, V; Chen, A; Cheon, BG; Chilikin, K; Cho, K; Choi, SK; Choi, Y; Cinabro, D; Czank, T; Dash, N; Di Carlo, S; Doležal, Z; Dutta, D; Eidelman, S; Fast, JE; Ferber, T; Fulsom, BG; Garg, R; Gaur, V; Gabyshev, N; Garmash, A; Gelb, M; Goldenzweig, P; Greenwald, D; Guido, E; Haba, J; Hayasaka, K; Hayashii, H; Hedges, MT; Hirose, S; Hou, WS; Iijima, T; Inami, K; Inguglia, G; Ishikawa, A; Itoh, R; Iwasaki, M; Jaegle, I; Jeon, HB; Jia, S; Jin, Y; Joo, KK; Julius, T; Kang, KH; Karyan, G; Kawasaki, T; Kiesling, C; Kim, DY; Kim, JB; Kim, SH; Kim, YJ; Kinoshita, K; Kodyš, P; Korpar, S; Kotchetkov, D; Križan, P; Kroeger, R; Krokovny, P; Kulasiri, R; Kuzmin, A; Kwon, YJ; Lange, JS; Lee, IS; Li, LK; Li, Y; Gioi, LL; Libby, J; Liventsev, D; Masuda, M; Merola, M; Miyabayashi, K; Miyata, H; Mohanty, GB; Moon, HK; Mori, T; Mussa, R

Published Date

  • February 1, 2018

Published In

Volume / Issue

  • 2018 / 2

Electronic International Standard Serial Number (EISSN)

  • 2050-3911

Digital Object Identifier (DOI)

  • 10.1093/ptep/pty003

Citation Source

  • Scopus