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arXiv · 2103.11540

Search for the charged lepton flavor violating decay $J/\psi\to e\tau$

BESIII Collaboration·M. Ablikim·M. N. Achasov·P. Adlarson·S. Ahmed·M. Albrecht·R. Aliberti·A. Amoroso·M. R. An·Q. An·X. H. Bai·Y. Bai·O. Bakina·R. Baldini Ferroli·I. Balossino·Y. Ban·V. Batozskaya·D. Becker·K. Begzsuren·N. Berger·M. Bertani·D. Bettoni·F. Bianchi·J. Bloms·A. Bortone·I. Boyko·R. A. Briere·H. Cai·X. Cai·A. Calcaterra·G. F. Cao·N. Cao·S. A. Cetin·J. F. Chang·W. L. Chang·G. Chelkov·C. Chen·D. Y. Chen·G. Chen·H. S. Chen·M. L. Chen·S. J. Chen·T. Chen·X. R. Chen·X. T. Chen·Y. B. Chen·Z. J Chen·W. S. Cheng·G. Cibinetto·F. Cossio·X. F. Cui·H. L. Dai·X. C. Dai·A. Dbeyssi·R. E. de Boer·D. Dedovich·Z. Y. Deng·A. Denig·I. Denysenko·M. Destefanis·F. De Mori·Y. Ding·C. Dong·J. Dong·L. Y. Dong·M. Y. Dong·X. Dong·S. X. Du·P. Egorov·Y. L. Fan·J. Fang·S. S. Fang·Y. Fang·R. Farinelli·L. Fava·F. Feldbauer·G. Felici·C. Q. Feng·J. H. Feng·K Fischer·M. Fritsch·C. D. Fu·Y. Gao·Y. G. Gao·I. Garzia·P. T. Ge·C. Geng·E. M. Gersabeck·A Gilman·K. Goetzen·L. Gong·W. X. Gong·W. Gradl·M. Greco·M. H. Gu·C. Y Guan·A. Q. Guo·C. J. Guo·L. B. Guo·R. P. Guo
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Abstract

A search for the charged lepton flavor violating decay $J/\psi\to e^{\pm}\tau^{\mp}$ with $\tau^{\mp} \to \pi^{\mp}\pi^0\nu_{\tau}$ is performed with about $10$ billion $J/ \psi$ events collected with the BESIII detector at the BEPCII. No significant signal is observed, and an upper limit is set on the branching fraction $\mathcal{B}(J/\psi\to e^{\pm}\tau^{\mp})<7.5\times10^{-8}$ at the 90$\%$ confidence level. This improves the previously published limit by two orders of magnitude.

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BESIII Collaboration, M. Ablikim, M. N. Achasov, P. Adlarson, S. Ahmed, M. Albrecht, R. Aliberti, A. Amoroso, M. R. An, Q. An, X. H. Bai, Y. Bai, O. Bakina, R. Baldini Ferroli, I. Balossino, Y. Ban, V. Batozskaya, D. Becker, K. Begzsuren, N. Berger, M. Bertani, D. Bettoni, F. Bianchi, J. Bloms, A. Bortone, I. Boyko, R. A. Briere, H. Cai, X. Cai, A. Calcaterra, G. F. Cao, N. Cao, S. A. Cetin, J. F. Chang, W. L. Chang, G. Chelkov, C. Chen, D. Y. Chen, G. Chen, H. S. Chen, M. L. Chen, S. J. Chen, T. Chen, X. R. Chen, X. T. Chen, Y. B. Chen, Z. J Chen, W. S. Cheng, G. Cibinetto, F. Cossio, X. F. Cui, H. L. Dai, X. C. Dai, A. Dbeyssi, R. E. de Boer, D. Dedovich, Z. Y. Deng, A. Denig, I. Denysenko, M. Destefanis, F. De Mori, Y. Ding, C. Dong, J. Dong, L. Y. Dong, M. Y. Dong, X. Dong, S. X. Du, P. Egorov, Y. L. Fan, J. Fang, S. S. Fang, Y. Fang, R. Farinelli, L. Fava, F. Feldbauer, G. Felici, C. Q. Feng, J. H. Feng, K Fischer, M. Fritsch, C. D. Fu, Y. Gao, Y. G. Gao, I. Garzia, P. T. Ge, C. Geng, E. M. Gersabeck, A Gilman, K. Goetzen, L. Gong, W. X. Gong, W. Gradl, M. Greco, M. H. Gu, C. Y Guan, A. Q. Guo, C. J. Guo, L. B. Guo, R. P. Guo. 2021-03-22. Search for the charged lepton flavor violating decay $J/\psi\to e\tau$. https://doi.org/10.1103/physrevd.103.112007

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