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arXiv · 2010.15361

Search for lepton-number- and baryon-number-violating tau decays at Belle

D. Sahoo·G. B. Mohanty·K. Trabelsi·I. Adachi·K. Adamczyk·H. Aihara·S. Al Said·D. M. Asner·T. Aushev·R. Ayad·T. Aziz·V. Babu·S. Bahinipati·P. Behera·J. Bennett·M. Bessner·V. Bhardwaj·T. Bilka·J. Biswal·G. Bonvicini·A. Bozek·M. Bračko·T. E. Browder·M. Campajola·L. Cao·D. Červenkov·M. -C. Chang·P. Chang·V. Chekelian·A. Chen·B. G. Cheon·K. Chilikin·H. E. Cho·K. Cho·S. -K. Choi·Y. Choi·S. Choudhury·D. Cinabro·S. Cunliffe·S. Das·N. Dash·G. De Nardo·F. Di Capua·J. Dingfelder·Z. Doležal·T. V. Dong·S. Dubey·S. Eidelman·D. Epifanov·T. Ferber·D. Ferlewicz·A. Frey·B. G. Fulsom·R. Garg·V. Gaur·A. Garmash·A. Giri·P. Goldenzweig·B. Golob·Y. Guan·K. Gudkova·C. Hadjivasiliou·S. Halder·T. Hara·O. Hartbrich·K. Hayasaka·H. Hayashii·M. T. Hedges·M. Hernandez Villanueva·W. -S. Hou·C. -L. Hsu·K. Huang·T. Iijima·K. Inami·G. Inguglia·A. Ishikawa·R. Itoh·M. Iwasaki·Y. Iwasaki·W. W. Jacobs·H. B. Jeon·S. Jia·Y. Jin·C. W. Joo·K. K. Joo·A. B. Kaliyar·K. H. Kang·G. Karyan·T. Kawasaki·H. Kichimi·C. Kiesling·D. Y. Kim·S. H. Kim·Y. -K. Kim·K. Kinoshita·P. Kodyš·T. Konno·S. Korpar·D. Kotchetkov·P. Križan
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Abstract

We search for lepton-number- and baryon-number-violating decays $\tau^{-}\to\overline{p}e^{+}e^{-}$, $pe^{-}e^{-}$, $\overline{p}e^{+}\mu^{-}$, $\overline{p}e^{-}\mu^{+}$, $\overline{p}\mu^{+}\mu^{-}$, and $p\mu^{-}\mu^{-}$ using 921 fb$^{-1}$ of data, equivalent to $(841\pm12)\times 10^6$ $\tau^{+}\tau^{-}$ events, recorded with the Belle detector at the KEKB asymmetric-energy $e^{+}e^{-}$ collider. In the absence of a signal, $90\%$ confidence-level upper limits are set on the branching fractions of these decays in the range $(1.8$-$4.0)\times 10^{-8}$. We set the world's first limits on the first four channels and improve the existing limits by an order of magnitude for the last two channels.

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D. Sahoo, G. B. Mohanty, K. Trabelsi, I. Adachi, K. Adamczyk, H. Aihara, S. Al Said, D. M. Asner, T. Aushev, R. Ayad, T. Aziz, V. Babu, S. Bahinipati, P. Behera, J. Bennett, M. Bessner, V. Bhardwaj, T. Bilka, J. Biswal, G. Bonvicini, A. Bozek, M. Bračko, T. E. Browder, M. Campajola, L. Cao, D. Červenkov, M. -C. Chang, P. Chang, V. Chekelian, A. Chen, B. G. Cheon, K. Chilikin, H. E. Cho, K. Cho, S. -K. Choi, Y. Choi, S. Choudhury, D. Cinabro, S. Cunliffe, S. Das, N. Dash, G. De Nardo, F. Di Capua, J. Dingfelder, Z. Doležal, T. V. Dong, S. Dubey, S. Eidelman, D. Epifanov, T. Ferber, D. Ferlewicz, A. Frey, B. G. Fulsom, R. Garg, V. Gaur, A. Garmash, A. Giri, P. Goldenzweig, B. Golob, Y. Guan, K. Gudkova, C. Hadjivasiliou, S. Halder, T. Hara, O. Hartbrich, K. Hayasaka, H. Hayashii, M. T. Hedges, M. Hernandez Villanueva, W. -S. Hou, C. -L. Hsu, K. Huang, T. Iijima, K. Inami, G. Inguglia, A. Ishikawa, R. Itoh, M. Iwasaki, Y. Iwasaki, W. W. Jacobs, H. B. Jeon, S. Jia, Y. Jin, C. W. Joo, K. K. Joo, A. B. Kaliyar, K. H. Kang, G. Karyan, T. Kawasaki, H. Kichimi, C. Kiesling, D. Y. Kim, S. H. Kim, Y. -K. Kim, K. Kinoshita, P. Kodyš, T. Konno, S. Korpar, D. Kotchetkov, P. Križan. 2020-10-29. Search for lepton-number- and baryon-number-violating tau decays at Belle. https://doi.org/10.1103/physrevd.102.111101

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