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

N. Shimizu, H. Aihara, D. Epifanov, I. Adachi, S. Al Said, D. M. Asner, V. Aulchenko, T. Aushev, R. Ayad, V. Babu, I. Badhrees, A. M. Bakich, V. Bansa, E. Barberio, V. Bhardwaj, B. Bhuyan, J. Biswal, A. Bobrov, A. Bozek, M. Bračko & 151 others T. E. Browder, D. Červenkov, M. C. Chang, P. Chang, V. Chekelian, A. Chen, B. G. Cheon, K. Chilikin, K. Cho, S. K. Choi, Y. Choi, D. Cinabro, T. Czank, N. Dash, S. Di Carlo, Z. Doležal, D. Dutta, S. Eidelman, J. E. Fast, T. Ferber, B. G. Fulsom, R. Garg, V. Gaur, N. Gabyshev, A. Garmash, M. Gelb, P. Goldenzweig, D. Greenwald, E. Guido, J. Haba, K. Hayasaka, H. Hayashii, M. T. Hedges, S. Hirose, W. S. Hou, T. Iijima, K. Inami, G. Inguglia, A. Ishikawa, R. Itoh, M. Iwasaki, I. Jaegle, H. B. Jeon, S. Jia, Y. Jin, K. K. Joo, T. Julius, K. H. Kang, G. Karyan, T. Kawasaki, C. Kiesling, D. Y. Kim, J. B. Kim, S. H. Kim, Y. J. Kim, K. Kinoshita, P. Kodyš, S. Korpar, D. Kotchetkov, P. Križan, R. Kroeger, P. Krokovny, R. Kulasiri, A. Kuzmin, Y. J. Kwon, J. S. Lange, I. S. Lee, L. K. Li, Y. Li, L. Li Gioi, J. Libby, D. Liventsev, M. Masuda, M. Merola, K. Miyabayashi, H. Miyata, G. B. Mohanty, H. K. Moon, T. Mori, R. Mussa, E. Nakano, M. Nakao, T. Nanut, K. J. Nath, Z. Natkaniec, M. Nayak, M. Niiyama, N. K. Nisar, S. Nishida, S. Ogawa, S. Okuno, H. Ono, G. Pakhlova, B. Pal, C. W. Park, H. Park, S. Paul, T. K. Pedlar, R. Pestotnik, L. E. Piilonen, V. Popov, M. Ritter, A. Rostomyan, Y. Sakai, M. Salehi, S. Sandilya, Y. Sato, V. Savinov, O. Schneider, G. Schnell, C. Schwanda, Y. Seino, K. Senyo, M. E. Sevior, V. Shebalin, T. A. Shibata, J. G. Shiu, B. Shwartz, A. Sokolov, E. Solovieva, M. Starič, J. F. Strube, K. Sumisawa, T. Sumiyoshi, U. Tamponi, K. Tanida, F. Tenchini, K. Trabelsi, M. Uchida, T. Uglov, Y. Unno, S. Uno, Y. Usov, C. Van Hulse, G. Varner, V. Vorobyev, A. Vossen, C. H. Wang, M. Z. Wang, P. Wang, M. Watanabe, E. Widmann, Eunil Won, Y. Yamashita, H. Ye, C. Z. Yuan, Z. P. Zhang, V. Zhilich, V. Zhukova, V. Zhulanov, A. Zupanc

Research output: Contribution to journalArticle

Abstract

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.

Original languageEnglish
JournalProgress of Theoretical and Experimental Physics
Volume2018
Issue number2
DOIs
Publication statusPublished - 2018 Feb 1

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decay
leptons
kinematics
collisions
detectors
predictions

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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Measurement of the τ Michel parameters η and ξκ in the radiative leptonic decay τ - → l - ν τ ν l γ . / Shimizu, N.; Aihara, H.; Epifanov, D.; Adachi, I.; Said, S. Al; Asner, D. M.; Aulchenko, V.; Aushev, T.; Ayad, R.; Babu, V.; Badhrees, I.; Bakich, A. M.; Bansa, V.; Barberio, E.; Bhardwaj, V.; Bhuyan, B.; Biswal, J.; Bobrov, A.; Bozek, A.; Bračko, M.; Browder, T. E.; Červenkov, D.; Chang, M. C.; Chang, P.; Chekelian, V.; Chen, A.; Cheon, B. G.; Chilikin, K.; Cho, K.; Choi, S. K.; Choi, Y.; Cinabro, D.; Czank, T.; Dash, N.; Di Carlo, S.; Doležal, Z.; Dutta, D.; Eidelman, S.; Fast, J. E.; Ferber, T.; Fulsom, B. G.; Garg, R.; Gaur, V.; Gabyshev, N.; Garmash, A.; Gelb, M.; Goldenzweig, P.; Greenwald, D.; Guido, E.; Haba, J.; Hayasaka, K.; Hayashii, H.; Hedges, M. T.; Hirose, S.; Hou, W. S.; Iijima, T.; Inami, K.; Inguglia, G.; Ishikawa, A.; Itoh, R.; Iwasaki, M.; Jaegle, I.; Jeon, H. B.; Jia, S.; Jin, Y.; Joo, K. K.; Julius, T.; Kang, K. H.; Karyan, G.; Kawasaki, T.; Kiesling, C.; Kim, D. Y.; Kim, J. B.; Kim, S. H.; Kim, Y. J.; Kinoshita, K.; Kodyš, P.; Korpar, S.; Kotchetkov, D.; Križan, P.; Kroeger, R.; Krokovny, P.; Kulasiri, R.; Kuzmin, A.; Kwon, Y. J.; Lange, J. S.; Lee, I. S.; Li, L. K.; Li, Y.; Gioi, L. Li; Libby, J.; Liventsev, D.; Masuda, M.; Merola, M.; Miyabayashi, K.; Miyata, H.; Mohanty, G. B.; Moon, H. K.; Mori, T.; Mussa, R.; Nakano, E.; Nakao, M.; Nanut, T.; Nath, K. J.; Natkaniec, Z.; Nayak, M.; Niiyama, M.; Nisar, N. K.; Nishida, S.; Ogawa, S.; Okuno, S.; Ono, H.; Pakhlova, G.; Pal, B.; Park, C. W.; Park, H.; Paul, S.; Pedlar, T. K.; Pestotnik, R.; Piilonen, L. E.; Popov, V.; Ritter, M.; Rostomyan, A.; Sakai, Y.; Salehi, M.; Sandilya, S.; Sato, Y.; Savinov, V.; Schneider, O.; Schnell, G.; Schwanda, C.; Seino, Y.; Senyo, K.; Sevior, M. E.; Shebalin, V.; Shibata, T. A.; Shiu, J. G.; Shwartz, B.; Sokolov, A.; Solovieva, E.; Starič, M.; Strube, J. F.; Sumisawa, K.; Sumiyoshi, T.; Tamponi, U.; Tanida, K.; Tenchini, F.; Trabelsi, K.; Uchida, M.; Uglov, T.; Unno, Y.; Uno, S.; Usov, Y.; Van Hulse, C.; Varner, G.; Vorobyev, V.; Vossen, A.; Wang, C. H.; Wang, M. Z.; Wang, P.; Watanabe, M.; Widmann, E.; Won, Eunil; Yamashita, Y.; Ye, H.; Yuan, C. Z.; Zhang, Z. P.; Zhilich, V.; Zhukova, V.; Zhulanov, V.; Zupanc, A.

In: Progress of Theoretical and Experimental Physics, Vol. 2018, No. 2, 01.02.2018.

Research output: Contribution to journalArticle

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, Nakano, E, Nakao, M, Nanut, T, Nath, KJ, Natkaniec, Z, Nayak, M, Niiyama, M, Nisar, NK, Nishida, S, Ogawa, S, Okuno, S, Ono, H, Pakhlova, G, Pal, B, Park, CW, Park, H, Paul, S, Pedlar, TK, Pestotnik, R, Piilonen, LE, Popov, V, Ritter, M, Rostomyan, A, Sakai, Y, Salehi, M, Sandilya, S, Sato, Y, Savinov, V, Schneider, O, Schnell, G, Schwanda, C, Seino, Y, Senyo, K, Sevior, ME, Shebalin, V, Shibata, TA, Shiu, JG, Shwartz, B, Sokolov, A, Solovieva, E, Starič, M, Strube, JF, Sumisawa, K, Sumiyoshi, T, Tamponi, U, Tanida, K, Tenchini, F, Trabelsi, K, Uchida, M, Uglov, T, Unno, Y, Uno, S, Usov, Y, Van Hulse, C, Varner, G, Vorobyev, V, Vossen, A, Wang, CH, Wang, MZ, Wang, P, Watanabe, M, Widmann, E, Won, E, Yamashita, Y, Ye, H, Yuan, CZ, Zhang, ZP, Zhilich, V, Zhukova, V, Zhulanov, V & Zupanc, A 2018, ' Measurement of the τ Michel parameters η and ξκ in the radiative leptonic decay τ - → l - ν τ ν l γ ', Progress of Theoretical and Experimental Physics, vol. 2018, no. 2. https://doi.org/10.1093/ptep/pty003
Shimizu, N. ; Aihara, H. ; Epifanov, D. ; Adachi, I. ; Said, S. Al ; Asner, D. M. ; Aulchenko, V. ; Aushev, T. ; Ayad, R. ; Babu, V. ; Badhrees, I. ; Bakich, A. M. ; Bansa, V. ; Barberio, E. ; Bhardwaj, V. ; Bhuyan, B. ; Biswal, J. ; Bobrov, A. ; Bozek, A. ; Bračko, M. ; Browder, T. E. ; Červenkov, D. ; Chang, M. C. ; Chang, P. ; Chekelian, V. ; Chen, A. ; Cheon, B. G. ; Chilikin, K. ; Cho, K. ; Choi, S. K. ; Choi, Y. ; Cinabro, D. ; Czank, T. ; Dash, N. ; Di Carlo, S. ; Doležal, Z. ; Dutta, D. ; Eidelman, S. ; Fast, J. E. ; Ferber, T. ; Fulsom, B. G. ; Garg, R. ; Gaur, V. ; Gabyshev, N. ; Garmash, A. ; Gelb, M. ; Goldenzweig, P. ; Greenwald, D. ; Guido, E. ; Haba, J. ; Hayasaka, K. ; Hayashii, H. ; Hedges, M. T. ; Hirose, S. ; Hou, W. S. ; Iijima, T. ; Inami, K. ; Inguglia, G. ; Ishikawa, A. ; Itoh, R. ; Iwasaki, M. ; Jaegle, I. ; Jeon, H. B. ; Jia, S. ; Jin, Y. ; Joo, K. K. ; Julius, T. ; Kang, K. H. ; Karyan, G. ; Kawasaki, T. ; Kiesling, C. ; Kim, D. Y. ; Kim, J. B. ; Kim, S. H. ; Kim, Y. J. ; Kinoshita, K. ; Kodyš, P. ; Korpar, S. ; Kotchetkov, D. ; Križan, P. ; Kroeger, R. ; Krokovny, P. ; Kulasiri, R. ; Kuzmin, A. ; Kwon, Y. J. ; Lange, J. S. ; Lee, I. S. ; Li, L. K. ; Li, Y. ; Gioi, L. Li ; Libby, J. ; Liventsev, D. ; Masuda, M. ; Merola, M. ; Miyabayashi, K. ; Miyata, H. ; Mohanty, G. B. ; Moon, H. K. ; Mori, T. ; Mussa, R. ; Nakano, E. ; Nakao, M. ; Nanut, T. ; Nath, K. J. ; Natkaniec, Z. ; Nayak, M. ; Niiyama, M. ; Nisar, N. K. ; Nishida, S. ; Ogawa, S. ; Okuno, S. ; Ono, H. ; Pakhlova, G. ; Pal, B. ; Park, C. W. ; Park, H. ; Paul, S. ; Pedlar, T. K. ; Pestotnik, R. ; Piilonen, L. E. ; Popov, V. ; Ritter, M. ; Rostomyan, A. ; Sakai, Y. ; Salehi, M. ; Sandilya, S. ; Sato, Y. ; Savinov, V. ; Schneider, O. ; Schnell, G. ; Schwanda, C. ; Seino, Y. ; Senyo, K. ; Sevior, M. E. ; Shebalin, V. ; Shibata, T. A. ; Shiu, J. G. ; Shwartz, B. ; Sokolov, A. ; Solovieva, E. ; Starič, M. ; Strube, J. F. ; Sumisawa, K. ; Sumiyoshi, T. ; Tamponi, U. ; Tanida, K. ; Tenchini, F. ; Trabelsi, K. ; Uchida, M. ; Uglov, T. ; Unno, Y. ; Uno, S. ; Usov, Y. ; Van Hulse, C. ; Varner, G. ; Vorobyev, V. ; Vossen, A. ; Wang, C. H. ; Wang, M. Z. ; Wang, P. ; Watanabe, M. ; Widmann, E. ; Won, Eunil ; Yamashita, Y. ; Ye, H. ; Yuan, C. Z. ; Zhang, Z. P. ; Zhilich, V. ; Zhukova, V. ; Zhulanov, V. ; Zupanc, A. / Measurement of the τ Michel parameters η and ξκ in the radiative leptonic decay τ - → l - ν τ ν l γ In: Progress of Theoretical and Experimental Physics. 2018 ; Vol. 2018, No. 2.
@article{f2f091bc05854203a19329372d2621e0,
title = "Measurement of the τ Michel parameters η and ξκ in the radiative leptonic decay τ - → l - ν τ ν l γ",
abstract = "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.",
author = "N. Shimizu and H. Aihara and D. Epifanov and I. Adachi and Said, {S. Al} and Asner, {D. M.} and V. Aulchenko and T. Aushev and R. Ayad and V. Babu and I. Badhrees and Bakich, {A. M.} and V. Bansa and E. Barberio and V. Bhardwaj and B. Bhuyan and J. Biswal and A. Bobrov and A. Bozek and M. Bračko and Browder, {T. E.} and D. Červenkov and Chang, {M. C.} and P. Chang and V. Chekelian and A. Chen and Cheon, {B. G.} and K. Chilikin and K. Cho and Choi, {S. K.} and Y. Choi and D. Cinabro and T. Czank and N. Dash and {Di Carlo}, S. and Z. Doležal and D. Dutta and S. Eidelman and Fast, {J. E.} and T. Ferber and Fulsom, {B. G.} and R. Garg and V. Gaur and N. Gabyshev and A. Garmash and M. Gelb and P. Goldenzweig and D. Greenwald and E. Guido and J. Haba and K. Hayasaka and H. Hayashii and Hedges, {M. T.} and S. Hirose and Hou, {W. S.} and T. Iijima and K. Inami and G. Inguglia and A. Ishikawa and R. Itoh and M. Iwasaki and I. Jaegle and Jeon, {H. B.} and S. Jia and Y. Jin and Joo, {K. K.} and T. Julius and Kang, {K. H.} and G. Karyan and T. Kawasaki and C. Kiesling and Kim, {D. Y.} and Kim, {J. B.} and Kim, {S. H.} and Kim, {Y. J.} and K. Kinoshita and P. Kodyš and S. Korpar and D. Kotchetkov and P. Križan and R. Kroeger and P. Krokovny and R. Kulasiri and A. Kuzmin and Kwon, {Y. J.} and Lange, {J. S.} and Lee, {I. S.} and Li, {L. K.} and Y. Li and Gioi, {L. Li} and J. Libby and D. Liventsev and M. Masuda and M. Merola and K. Miyabayashi and H. Miyata and Mohanty, {G. B.} and Moon, {H. K.} and T. Mori and R. Mussa and E. Nakano and M. Nakao and T. Nanut and Nath, {K. J.} and Z. Natkaniec and M. Nayak and M. Niiyama and Nisar, {N. K.} and S. Nishida and S. Ogawa and S. Okuno and H. Ono and G. Pakhlova and B. Pal and Park, {C. W.} and H. Park and S. Paul and Pedlar, {T. K.} and R. Pestotnik and Piilonen, {L. E.} and V. Popov and M. Ritter and A. Rostomyan and Y. Sakai and M. Salehi and S. Sandilya and Y. Sato and V. Savinov and O. Schneider and G. Schnell and C. Schwanda and Y. Seino and K. Senyo and Sevior, {M. E.} and V. Shebalin and Shibata, {T. A.} and Shiu, {J. G.} and B. Shwartz and A. Sokolov and E. Solovieva and M. Starič and Strube, {J. F.} and K. Sumisawa and T. Sumiyoshi and U. Tamponi and K. Tanida and F. Tenchini and K. Trabelsi and M. Uchida and T. Uglov and Y. Unno and S. Uno and Y. Usov and {Van Hulse}, C. and G. Varner and V. Vorobyev and A. Vossen and Wang, {C. H.} and Wang, {M. Z.} and P. Wang and M. Watanabe and E. Widmann and Eunil Won and Y. Yamashita and H. Ye and Yuan, {C. Z.} and Zhang, {Z. P.} and V. Zhilich and V. Zhukova and V. Zhulanov and A. Zupanc",
year = "2018",
month = "2",
day = "1",
doi = "10.1093/ptep/pty003",
language = "English",
volume = "2018",
journal = "Progress of Theoretical and Experimental Physics",
issn = "2050-3911",
publisher = "Oxford University Press",
number = "2",

}

TY - JOUR

T1 - Measurement of the τ Michel parameters η and ξκ in the radiative leptonic decay τ - → l - ν τ ν l γ

AU - Shimizu, N.

AU - Aihara, H.

AU - Epifanov, D.

AU - Adachi, I.

AU - Said, S. Al

AU - Asner, D. M.

AU - Aulchenko, V.

AU - Aushev, T.

AU - Ayad, R.

AU - Babu, V.

AU - Badhrees, I.

AU - Bakich, A. M.

AU - Bansa, V.

AU - Barberio, E.

AU - Bhardwaj, V.

AU - Bhuyan, B.

AU - Biswal, J.

AU - Bobrov, A.

AU - Bozek, A.

AU - Bračko, M.

AU - Browder, T. E.

AU - Červenkov, D.

AU - Chang, M. C.

AU - Chang, P.

AU - Chekelian, V.

AU - Chen, A.

AU - Cheon, B. G.

AU - Chilikin, K.

AU - Cho, K.

AU - Choi, S. K.

AU - Choi, Y.

AU - Cinabro, D.

AU - Czank, T.

AU - Dash, N.

AU - Di Carlo, S.

AU - Doležal, Z.

AU - Dutta, D.

AU - Eidelman, S.

AU - Fast, J. E.

AU - Ferber, T.

AU - Fulsom, B. G.

AU - Garg, R.

AU - Gaur, V.

AU - Gabyshev, N.

AU - Garmash, A.

AU - Gelb, M.

AU - Goldenzweig, P.

AU - Greenwald, D.

AU - Guido, E.

AU - Haba, J.

AU - Hayasaka, K.

AU - Hayashii, H.

AU - Hedges, M. T.

AU - Hirose, S.

AU - Hou, W. S.

AU - Iijima, T.

AU - Inami, K.

AU - Inguglia, G.

AU - Ishikawa, A.

AU - Itoh, R.

AU - Iwasaki, M.

AU - Jaegle, I.

AU - Jeon, H. B.

AU - Jia, S.

AU - Jin, Y.

AU - Joo, K. K.

AU - Julius, T.

AU - Kang, K. H.

AU - Karyan, G.

AU - Kawasaki, T.

AU - Kiesling, C.

AU - Kim, D. Y.

AU - Kim, J. B.

AU - Kim, S. H.

AU - Kim, Y. J.

AU - Kinoshita, K.

AU - Kodyš, P.

AU - Korpar, S.

AU - Kotchetkov, D.

AU - Križan, P.

AU - Kroeger, R.

AU - Krokovny, P.

AU - Kulasiri, R.

AU - Kuzmin, A.

AU - Kwon, Y. J.

AU - Lange, J. S.

AU - Lee, I. S.

AU - Li, L. K.

AU - Li, Y.

AU - Gioi, L. Li

AU - Libby, J.

AU - Liventsev, D.

AU - Masuda, M.

AU - Merola, M.

AU - Miyabayashi, K.

AU - Miyata, H.

AU - Mohanty, G. B.

AU - Moon, H. K.

AU - Mori, T.

AU - Mussa, R.

AU - Nakano, E.

AU - Nakao, M.

AU - Nanut, T.

AU - Nath, K. J.

AU - Natkaniec, Z.

AU - Nayak, M.

AU - Niiyama, M.

AU - Nisar, N. K.

AU - Nishida, S.

AU - Ogawa, S.

AU - Okuno, S.

AU - Ono, H.

AU - Pakhlova, G.

AU - Pal, B.

AU - Park, C. W.

AU - Park, H.

AU - Paul, S.

AU - Pedlar, T. K.

AU - Pestotnik, R.

AU - Piilonen, L. E.

AU - Popov, V.

AU - Ritter, M.

AU - Rostomyan, A.

AU - Sakai, Y.

AU - Salehi, M.

AU - Sandilya, S.

AU - Sato, Y.

AU - Savinov, V.

AU - Schneider, O.

AU - Schnell, G.

AU - Schwanda, C.

AU - Seino, Y.

AU - Senyo, K.

AU - Sevior, M. E.

AU - Shebalin, V.

AU - Shibata, T. A.

AU - Shiu, J. G.

AU - Shwartz, B.

AU - Sokolov, A.

AU - Solovieva, E.

AU - Starič, M.

AU - Strube, J. F.

AU - Sumisawa, K.

AU - Sumiyoshi, T.

AU - Tamponi, U.

AU - Tanida, K.

AU - Tenchini, F.

AU - Trabelsi, K.

AU - Uchida, M.

AU - Uglov, T.

AU - Unno, Y.

AU - Uno, S.

AU - Usov, Y.

AU - Van Hulse, C.

AU - Varner, G.

AU - Vorobyev, V.

AU - Vossen, A.

AU - Wang, C. H.

AU - Wang, M. Z.

AU - Wang, P.

AU - Watanabe, M.

AU - Widmann, E.

AU - Won, Eunil

AU - Yamashita, Y.

AU - Ye, H.

AU - Yuan, C. Z.

AU - Zhang, Z. P.

AU - Zhilich, V.

AU - Zhukova, V.

AU - Zhulanov, V.

AU - Zupanc, A.

PY - 2018/2/1

Y1 - 2018/2/1

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=85062193441&partnerID=8YFLogxK

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U2 - 10.1093/ptep/pty003

DO - 10.1093/ptep/pty003

M3 - Article

VL - 2018

JO - Progress of Theoretical and Experimental Physics

JF - Progress of Theoretical and Experimental Physics

SN - 2050-3911

IS - 2

ER -