Search for Lepton-Flavor-Violating τ Decays to a Lepton and an Invisible Boson at Belle II.
I Adachi, K Adamczyk, L Aggarwal, H Ahmed, H Aihara, N Akopov, A Aloisio, N Anh Ky, D M Asner, T Aushev, V Aushev, H Bae, S Bahinipati, P Bambade, Sw Banerjee, J Baudot, M Bauer, A Baur, A Beaubien, J Becker, P K Behera, J V Bennett, E Bernieri, F U Bernlochner, V Bertacchi, M Bertemes, E Bertholet, M Bessner, S Bettarini, B Bhuyan, F Bianchi, T Bilka, S Bilokin, D Biswas, D Bodrov, A Bolz, J Borah, A Bozek, M Bračko, P Branchini, T E Browder, A Budano, S Bussino, M Campajola, L Cao, G Casarosa, C Cecchi, M-C Chang, P Chang, R Cheaib, P Cheema, V Chekelian, Y Q Chen, B G Cheon, K Chilikin, K Chirapatpimol, H-E Cho, K Cho, S-J Cho, S-K Choi, S Choudhury, D Cinabro, L Corona, S Cunliffe, S Das, F Dattola, E De La Cruz-Burelo, S A De La Motte, G De Nardo, M De Nuccio, G De Pietro, R de Sangro, M Destefanis, S Dey, A De Yta-Hernandez, R Dhamija, A Di Canto, F Di Capua, J Dingfelder, Z Doležal, I Domínguez Jiménez, T V Dong, M Dorigo, K Dort, D Dossett, S Dreyer, S Dubey, G Dujany, P Ecker, M Eliachevitch, D Epifanov, P Feichtinger, T Ferber, D Ferlewicz, T Fillinger, C Finck, G Finocchiaro, K Flood, A Fodor, F Forti, B G Fulsom, A Gabrielli, E Ganiev, M Garcia-Hernandez, V Gaur, A Gaz, A Gellrich, G Ghevondyan, R Giordano, A Giri, A Glazov, B Gobbo, R Godang, P Goldenzweig, W Gradl, S Granderath, E Graziani, D Greenwald, Z Gruberová, T Gu, K Gudkova, J Guilliams, T Hara, K Hayasaka, H Hayashii, S Hazra, C Hearty, I Heredia de la Cruz, M Hernández Villanueva, A Hershenhorn, T Higuchi, E C Hill, M Hohmann, C-L Hsu, T Humair, T Iijima, K Inami, G Inguglia, N Ipsita, A Ishikawa, S Ito, R Itoh, M Iwasaki, P Jackson, W W Jacobs, D E Jaffe, E-J Jang, Q P Ji, S Jia, Y Jin, K K Joo, H Junkerkalefeld, H Kakuno, A B Kaliyar, J Kandra, K H Kang, S Kang, R Karl, G Karyan, C Kiesling, C-H Kim, D Y Kim, K-H Kim, Y-K Kim, H Kindo, K Kinoshita, P Kodyš, T Koga, S Kohani, K Kojima, T Konno, A Korobov, S Korpar, E Kovalenko, R Kowalewski, T M G Kraetzschmar, P Križan, P Krokovny, T Kuhr, J Kumar, R Kumar, K Kumara, T Kunigo, A Kuzmin, Y-J Kwon, S Lacaprara, T Lam, L Lanceri, J S Lange, M Laurenza, K Lautenbach, R Leboucher, F R Le Diberder, P Leitl, P M Lewis, C Li, L K Li, Y B Li, J Libby, K Lieret, Z Liptak, Q Y Liu, D Liventsev, S Longo, A Lozar, T Lueck, T Luo, C Lyu, M Maggiora, R Maiti, S Maity, R Manfredi, E Manoni, A Manthei, S Marcello, C Marinas, L Martel, A Martini, T Martinov, L Massaccesi, M Masuda, T Matsuda, K Matsuoka, D Matvienko, S K Maurya, J A McKenna, F Meier, M Merola, F Metzner, M Milesi, C Miller, K Miyabayashi, R Mizuk, G B Mohanty, N Molina-Gonzalez, S Moneta, H-G Moser, M Mrvar, R Mussa, I Nakamura, K R Nakamura, M Nakao, H Nakayama, Y Nakazawa, A Narimani Charan, M Naruki, A Natochii, L Nayak, M Nayak, G Nazaryan, C Niebuhr, N K Nisar, S Nishida, S Ogawa, H Ono, Y Onuki, P Oskin, P Pakhlov, G Pakhlova, A Paladino, A Panta, E Paoloni, S Pardi, K Parham, H Park, S-H Park, B Paschen, A Passeri, S Patra, S Paul, T K Pedlar, I Peruzzi, R Peschke, R Pestotnik, F Pham, M Piccolo, L E Piilonen, G Pinna Angioni, P L M Podesta-Lerma, T Podobnik, S Pokharel, L Polat, C Praz, S Prell, E Prencipe, M T Prim, H Purwar, N Rad, P Rados, G Raeuber, S Raiz, A Ramirez Morales, M Reif, S Reiter, M Remnev, I Ripp-Baudot, G Rizzo, S H Robertson, D Rodríguez Pérez, J M Roney, A Rostomyan, N Rout, G Russo, D A Sanders, S Sandilya, A Sangal, L Santelj, Y Sato, V Savinov, B Scavino, J Schueler, C Schwanda, Y Seino, A Selce, K Senyo, J Serrano, M E Sevior, C Sfienti, C P Shen, X D Shi, T Shillington, J-G Shiu, B Shwartz, A Sibidanov, F Simon, J B Singh, J Skorupa, R J Sobie, A Soffer, A Sokolov, E Solovieva, S Spataro, B Spruck, M Starič, S Stefkova, Z S Stottler, R Stroili, J Strube, Y Sue, M Sumihama, K Sumisawa, W Sutcliffe, S Y Suzuki, H Svidras, M Takizawa, U Tamponi, K Tanida, H Tanigawa, F Tenchini, A Thaller, R Tiwary, D Tonelli, E Torassa, N Toutounji, K Trabelsi, M Uchida, I Ueda, Y Uematsu, T Uglov, K Unger, Y Unno, K Uno, S Uno, Y Ushiroda, S E Vahsen, R van Tonder, G S Varner, K E Varvell, A Vinokurova, L Vitale, V Vobbilisetti, H M Wakeling, E Wang, M-Z Wang, X L Wang, A Warburton, M Watanabe, S Watanuki, M Welsch, C Wessel, J Wiechczynski, X P Xu, B D Yabsley, S Yamada, W Yan, S B Yang, H Ye, J Yelton, J H Yin, Y M Yook, K Yoshihara, C Z Yuan, Y Yusa, L Zani, Y Zhang, V Zhilich, Q D Zhou, X Y Zhou, V I Zhukova, R Žlebčík
We search for lepton-flavor-violating τ^{-}→e^{-}α and τ^{-}→μ^{-}α decays, where α is an invisible spin-0 boson. The search uses electron-positron collisions at 10.58 GeV center-of-mass energy with an integrated luminosity of 62.8 fb^{-1}, produced by the SuperKEKB collider and collected with the Belle II detector. We search for an excess in the lepton-energy spectrum of the known τ^{-}→e^{-}ν[over ¯]_{e}ν_{τ} and τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ} decays. We report 95% confidence-level upper limits on the branching-fraction ratio B(τ^{-}→e^{-}α)/B(τ^{-}→e^{-}ν[over ¯]_{e}ν_{τ}) in the range (1.1-9.7)×10^{-3} and on B(τ^{-}→μ^{-}α)/B(τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ}) in the range (0.7-12.2)×10^{-3} for α masses between 0 and 1.6 GeV/c^{2}. These results provide the most stringent bounds on invisible boson production from τ decays.
Full text links
We have located links that may give you full text access.
Try logging in through your university/institutional subscription. For a smoother one-click institutional access experience, please use our mobile app.
