학술논문

Search for lepton-flavor-violating $\tau^- \to \ell^-\phi$ decays in 2019-2021 Belle II data
Document Type
Working Paper
Author
Belle II CollaborationAbudinén, F.Adachi, I.Adamczyk, K.Aggarwal, L.Ahlburg, P.Ahmed, H.Ahn, J. K.Aihara, H.Akopov, N.Aloisio, A.Andricek, L.Ky, N. AnhAsner, D. M.Atmacan, H.Aulchenko, V.Aushev, T.Aushev, V.Aversano, M.Babu, V.Bacher, S.Bae, H.Bahinipati, S.Bakich, A. M.Bambade, P.Banerjee, Sw.Bansal, S.Barrett, M.Batignani, G.Baudot, J.Bauer, M.Baur, A.Beaulieu, A.Becker, J.Behera, P. K.Bennett, J. V.Bernieri, E.Bernlochner, F. U.Bertacchi, V.Bertemes, M.Bertholet, E.Bessner, M.Bettarini, S.Bhardwaj, V.Bhuyan, B.Bianchi, F.Bilka, T.Bilokin, S.Biswas, D.Bobrov, A.Bodrov, D.Bolz, A.Bondar, A.Bonvicini, G.Borah, J.Bozek, A.Bračko, M.Branchini, P.Briere, R. A.Browder, T. E.Brown, D. N.Budano, A.Bussino, S.Campajola, M.Cao, L.Casarosa, G.Cecchi, C.Cerasoli, J.Červenkov, D.Chang, M. -C.Chang, P.Cheaib, R.Cheema, P.Chekelian, V.Chen, C.Chen, Y. Q.Chen, Y. -T.Cheon, B. G.Chilikin, K.Chirapatpimol, K.Cho, H. -E.Cho, K.Cho, S. -J.Choi, S. -K.Choudhury, S.Cinabro, D.Cochran, J.Corona, L.Cremaldi, L. M.Cunliffe, S.Czank, T.Das, S.Dattola, F.De La Cruz-Burelo, E.De La Motte, S. A.de Marino, G.De Nardo, G.De Nuccio, M.De Pietro, G.de Sangro, R.Deschamps, B.Destefanis, M.Dey, S.De Yta-Hernandez, A.Dhamija, R.Di Canto, A.Di Capua, F.Dingfelder, J.Doležal, Z.Jiménez, I. DomínguezDong, T. V.Dorigo, M.Dort, K.Dossett, D.Dreyer, S.Dubey, S.Duell, S.Dujany, G.Ecker, P.Eliachevitch, M.Epifanov, D.Feichtinger, P.Ferber, T.Ferlewicz, D.Fillinger, T.Finck, C.Finocchiaro, G.Fischer, P.Flood, K.Fodor, A.Forti, F.Frey, A.Friedl, M.Fulsom, B. G.Gabrielli, A.Gabyshev, N.Ganiev, E.Garcia-Hernandez, M.Garg, R.Garmash, A.Gaudino, G.Gaur, V.Gaz, A.Gebauer, U.Gellrich, A.Ghevondyan, G.Ghosh, D.Giakoustidis, G.Giordano, R.Giri, A.Glazov, A.Gobbo, B.Godang, R.Goldenzweig, P.Golob, B.Gong, G.Grace, P.Gradl, W.Graf-Schreiber, M.Grammatico, T.Granderath, S.Graziani, E.Greenwald, D.Gruberová, Z.Gu, T.Guan, Y.Gudkova, K.Hadjivasiliou, C.Halder, S.Han, Y.Hara, K.Hara, T.Hartbrich, O.Hayasaka, K.Hayashii, H.Hazra, S.Hearty, C.Hedges, M. T.de la Cruz, I. HerediaVillanueva, M. HernándezHershenhorn, A.Higuchi, T.Hill, E. C.Hirata, H.Hoek, M.Hohmann, M.Hotta, T.Hsu, C. -L.Huang, K.Humair, T.Iijima, T.Inami, K.Inguglia, G.Ipsita, N.Jabbar, J. IrakkathilIshikawa, A.Ito, S.Itoh, R.Iwasaki, M.Iwasaki, Y.Iwata, S.Jackson, P.Jacobs, W. W.Jaffe, D. E.Jang, E. -J.Jeon, H. B.Ji, Q. P.Jia, S.Jin, Y.Joo, K. K.Junkerkalefeld, H.Kadenko, I.Kakuno, H.Kaleta, M.Kalita, D.Kaliyar, A. B.Kandra, J.Kang, K. H.Kang, S.Kapusta, P.Karl, R.Karyan, G.Kato, Y.Kawasaki, T.Ketter, C.Kiesling, C.Kim, C. -H.Kim, D. Y.Kim, H. J.Kim, K. -H.Kim, Y. -K.Kim, Y. J.Kimmel, T. D.Kindo, H.Kinoshita, K.Kleinwort, C.Kodyš, P.Koga, T.Kohani, S.Kojima, K.Konno, T.Korobov, A.Korpar, S.Kovalenko, E.Kowalewski, R.Kraetzschmar, T. M. G.Križan, P.Krohn, J. F.Krokovny, P.Kuehn, W.Kuhr, T.Kumar, J.Kumar, M.Kumar, R.Kumara, K.Kumita, T.Kunigo, T.Kurz, S.Kuzmin, A.Kvasnička, P.Kwon, Y. -J.Lacaprara, S.Lai, Y. -T.La Licata, C.Lalwani, K.Lam, T.Lanceri, L.Lange, J. S.Laurenza, M.Lautenbach, K.Laycock, P. J.Leboucher, R.Diberder, F. R. LeLee, S. C.Leitl, P.Levit, D.Lewis, P. M.Li, C.Li, L. K.Li, S. X.Li, Y. B.Libby, J.Lieret, K.Lin, J.Liptak, Z.Liu, Q. Y.Liu, Z. A.Liu, Z. Q.Liventsev, D.Longo, S.Lozar, A.Lueck, T.Luo, T.Lyu, C.Ma, Y.Maggiora, M.Maharana, S. P.Maiti, R.Maity, S.Manfredi, R.Manoni, E.Manthei, A. C.Mantovano, M.Marcantonio, D.Marcello, S.Marinas, C.Martel, L.Martellini, C.Martini, A.Martinov, T.Massaccesi, L.Masuda, M.Matsuda, T.Matsuoka, K.Matvienko, D.Maurya, S. K.McKenna, J. A.McNeil, J.Meggendorfer, F.Meier, F.Merola, M.Metzner, F.Milesi, M.Miller, C.Miyabayashi, K.Miyake, H.Miyata, H.Mizuk, R.Mohanty, G. B.Molina-Gonzalez, N.Mondal, S.Moneta, S.Moon, H.Moser, H. -G.Mrvar, M.Muller, Th.Mussa, R.Nakamura, I.Nakamura, K. R.Nakano, E.Nakao, M.Nakayama, H.Nakazawa, H.Nakazawa, Y.Charan, A. NarimaniNaruki, M.Narwal, D.Natkaniec, Z.Natochii, A.Nayak, L.Nayak, M.Nazaryan, G.Niebuhr, C.Niiyama, M.Ninkovic, J.Nisar, N. K.Nishida, S.Nishimura, K.Nouxman, M. H. A.Ogawa, K.Ogawa, S.Olsen, S. L.Onishchuk, Y.Ono, H.Onuki, Y.Oskin, P.Oxford, E. R.Ozaki, H.Pakhlov, P.Pakhlova, G.Paladino, A.Pang, T.Panta, A.Paoloni, E.Pardi, S.Parham, K.Park, H.Park, S. -H.Paschen, B.Passeri, A.Pathak, A.Patra, S.Paul, S.Pedlar, T. K.Peruzzi, I.Peschke, R.Pestotnik, R.Pham, F.Piccolo, M.Piilonen, L. E.Angioni, G. PinnaPodesta-Lerma, P. L. M.Podobnik, T.Pokharel, S.Polat, L.Popov, V.Praz, C.Prell, S.Prencipe, E.Prim, M. T.Purohit, M. V.Purwar, H.Rad, N.Rados, P.Raeuber, G.Raiz, S.Morales, A. RamirezRauls, N.Reif, M.Reiter, S.Remnev, M.Ripp-Baudot, I.Ritter, M.Ritzert, M.Rizzo, G.Rizzuto, L. B.Robertson, S. H.Rocchetti, P.Pérez, D. RodríguezRoehrken, M.Roney, J. M.Rosenfeld, C.Rostomyan, A.Rout, N.Rozanska, M.Russo, G.Sahoo, D.Sakai, Y.Sanders, D. A.Sandilya, S.Sangal, A.Santelj, L.Sartori, P.Sato, Y.Savinov, V.Scavino, B.Schmitt, C.Schmitz, J.Schnepf, M.Schreeck, H.Schueler, J.Schwanda, C.Schwartz, A. J.Schwenker, B.Schwickardi, M.Seino, Y.Selce, A.Senyo, K.Serrano, J.Sevior, M. E.Sfienti, C.Shan, W.Sharma, C.Shebalin, V.Shen, C. P.Shi, X. D.Shibuya, H.Shillington, T.Shiu, J. -G.Shtol, D.Shwartz, B.Sibidanov, A.Simon, F.Singh, J. B.Skorupa, J.Smith, K.Sobie, R. J.Soffer, A.Sokolov, A.Soloviev, Y.Solovieva, E.Spataro, S.Spruck, B.Starič, M.Stavroulakis, P.Stefkova, S.Stottler, Z. S.Stroili, R.Strube, J.Stypula, J.Sue, Y.Sugiura, R.Sumihama, M.Sumisawa, K.Sutcliffe, W.Suzuki, S. Y.Svidras, H.Tabata, M.Takahashi, M.Takizawa, M.Tamponi, U.Tanaka, S.Tanida, K.Tanigawa, H.Taniguchi, N.Tao, Y.Tenchini, F.Thaller, A.Tittel, O.Tiwary, R.Tonelli, D.Torassa, E.Toutounji, N.Trabelsi, K.Tsaklidis, I.Tsuboyama, T.Tsuzuki, N.Uchida, M.Ueda, I.Uehara, S.Uematsu, Y.Ueno, T.Uglov, T.Unger, K.Unno, Y.Uno, K.Uno, S.Urquijo, P.Ushiroda, Y.Usov, Y. V.Vahsen, S. E.van Tonder, R.Varner, G. S.Varvell, K. E.Vinokurova, A.Vismaya, V. S.Vitale, L.Vobbilisetti, V.Vorobyev, V.Vossen, A.Wach, B.Waheed, E.Wakai, M.Wakeling, H. M.Wallner, S.Abdullah, W. WanWang, B.Wang, C. H.Wang, E.Wang, M. -Z.Wang, X. L.Wang, Z.Warburton, A.Watanabe, M.Watanuki, S.Webb, J.Wehle, S.Welsch, M.Werbycka, O.Wessel, C.Wiechczynski, J.Wieduwilt, P.Windel, H.Won, E.Wu, L. J.Xie, Y.Xu, X. P.Yabsley, B. D.Yamada, S.Yan, W.Yang, S. B.Yelton, J.Yin, J. H.Yook, Y. M.Yoshihara, K.Yuan, C. Z.Yusa, Y.Zani, L.Zhang, J. Z.Zhang, Y.Zhang, Z.Zhilich, V.Zhou, J. S.Zhou, Q. D.Zhou, X. Y.Zhukova, V. I.Zhulanov, V.Žlebčík, R.
Source
Subject
High Energy Physics - Experiment
Language
Abstract
We report a search for lepton-flavor-violating decays $\tau^- \to \ell^- \phi$ ($\ell^- =e^-,\mu^-$) at the Belle II experiment, using a sample of electron-positron data produced at the SuperKEKB collider in 2019-2021 and corresponding to an integrated luminosity of 190 fb$^{-1}$. We use a new untagged selection for $e^+e^- \to \tau^+\tau^-$ events, where the signal $\tau$ is searched for as a neutrinoless final state of a single charged lepton and a $\phi$ meson and the other $\tau$ is not reconstructed in any specific decay mode, in contrast to previous measurements by the BaBar and Belle experiments. We find no evidence for $\tau^- \to \ell^- \phi$ decays and obtain upper limits on the branching fractions at 90% confidence level of 23 $\times 10^{-8}$ and 9.7$\times 10^{-8}$ for $\tau^- \rightarrow e^-\phi$ and $\tau^- \rightarrow \mu^-\phi$, respectively