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arXiv · 1409.8548

Search for the lepton flavour violating decay $\tau^-\to \mu^-\mu^+\mu^-$

LHCb collaboration·R. Aaij·C. Abellán Beteta·B. Adeva·M. Adinolfi·A. Affolder·Z. Ajaltouni·S. Akar·J. Albrecht·F. Alessio·M. Alexander·S. Ali·G. Alkhazov·P. Alvarez Cartelle·A. A. Alves Jr·S. Amato·S. Amerio·Y. Amhis·L. An·L. Anderlini·J. Anderson·R. Andreassen·M. Andreotti·J. E. Andrews·R. B. Appleby·O. Aquines Gutierrez·F. Archilli·A. Artamonov·M. Artuso·E. Aslanides·G. Auriemma·M. Baalouch·S. Bachmann·J. J. Back·A. Badalov·C. Baesso·W. Baldini·R. J. Barlow·C. Barschel·S. Barsuk·W. Barter·V. Batozskaya·V. Battista·A. Bay·L. Beaucourt·J. Beddow·F. Bedeschi·I. Bediaga·S. Belogurov·K. Belous·I. Belyaev·E. Ben-Haim·G. Bencivenni·S. Benson·J. Benton·A. Berezhnoy·R. Bernet·M. -O. Bettler·M. van Beuzekom·A. Bien·S. Bifani·T. Bird·A. Bizzeti·P. M. Bjørnstad·T. Blake·F. Blanc·J. Blouw·S. Blusk·V. Bocci·A. Bondar·N. Bondar·W. Bonivento·S. Borghi·A. Borgia·M. Borsato·T. J. V. Bowcock·E. Bowen·C. Bozzi·T. Brambach·D. Brett·M. Britsch·T. Britton·J. Brodzicka·N. H. Brook·H. Brown·A. Bursche·G. Busetto·J. Buytaert·S. Cadeddu·R. Calabrese·M. Calvi·M. Calvo Gomez·P. Campana·D. Campora Perez·A. Carbone·G. Carboni·R. Cardinale·A. Cardini·L. Carson·K. Carvalho Akiba
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Abstract

A search for the lepton flavour violating decay $\tau^-\to \mu^-\mu^+\mu^-$ is performed with the LHCb experiment. The data sample corresponds to an integrated luminosity of $1.0\mathrm{\,fb}^{-1}$ of proton-proton collisions at a centre-of-mass energy of $7\mathrm{\,Te\kern -0.1em V}$ and $2.0\mathrm{\,fb}^{-1}$ at $8\mathrm{\,Te\kern -0.1em V}$. No evidence is found for a signal, and a limit is set at $90\%$ confidence level on the branching fraction, $\mathcal{B}(\tau^-\to \mu^-\mu^+\mu^-) < 4.6 \times 10^{-8}$.

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LHCb collaboration, R. Aaij, C. Abellán Beteta, B. Adeva, M. Adinolfi, A. Affolder, Z. Ajaltouni, S. Akar, J. Albrecht, F. Alessio, M. Alexander, S. Ali, G. Alkhazov, P. Alvarez Cartelle, A. A. Alves Jr, S. Amato, S. Amerio, Y. Amhis, L. An, L. Anderlini, J. Anderson, R. Andreassen, M. Andreotti, J. E. Andrews, R. B. Appleby, O. Aquines Gutierrez, F. Archilli, A. Artamonov, M. Artuso, E. Aslanides, G. Auriemma, M. Baalouch, S. Bachmann, J. J. Back, A. Badalov, C. Baesso, W. Baldini, R. J. Barlow, C. Barschel, S. Barsuk, W. Barter, V. Batozskaya, V. Battista, A. Bay, L. Beaucourt, J. Beddow, F. Bedeschi, I. Bediaga, S. Belogurov, K. Belous, I. Belyaev, E. Ben-Haim, G. Bencivenni, S. Benson, J. Benton, A. Berezhnoy, R. Bernet, M. -O. Bettler, M. van Beuzekom, A. Bien, S. Bifani, T. Bird, A. Bizzeti, P. M. Bjørnstad, T. Blake, F. Blanc, J. Blouw, S. Blusk, V. Bocci, A. Bondar, N. Bondar, W. Bonivento, S. Borghi, A. Borgia, M. Borsato, T. J. V. Bowcock, E. Bowen, C. Bozzi, T. Brambach, D. Brett, M. Britsch, T. Britton, J. Brodzicka, N. H. Brook, H. Brown, A. Bursche, G. Busetto, J. Buytaert, S. Cadeddu, R. Calabrese, M. Calvi, M. Calvo Gomez, P. Campana, D. Campora Perez, A. Carbone, G. Carboni, R. Cardinale, A. Cardini, L. Carson, K. Carvalho Akiba. 2014-09-30. Search for the lepton flavour violating decay $\tau^-\to \mu^-\mu^+\mu^-$. https://doi.org/10.1007/jhep02(2015)121

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