Search for the lepton flavour violating decay B + → K + μ − τ + using Bs2∗0 decays
Aaij R., Abellán Beteta C., Ackernley T., Adeva B., Adinolfi M., Afsharnia H., Aidala CA., Aiola S., Ajaltouni Z., Akar S., Albicocco P., Albrecht J., Alessio F., Alexander M., Alfonso Albero A., Alkhazov G., Alvarez Cartelle P., Alves AA., Amato S., Amhis Y., An L., Anderlini L., Andreassi G., Andreotti M., Archilli F., Artamonov A., Artuso M., Arzymatov K., Aslanides E., Atzeni M., Audurier B., Bachmann S., Back JJ., Baker S., Balagura V., Baldini W., Baranov A., Barlow RJ., Barsuk S., Barter W., Bartolini M., Baryshnikov F., Basels JM., Bassi G., Batozskaya V., Batsukh B., Battig A., Bay A., Becker M., Bedeschi F., Bediaga I., Beiter A., Bel LJ., Belavin V., Belin S., Bellee V., Belous K., Belyaev I., Bencivenni G., Ben-Haim E., Benson S., Beranek S., Berezhnoy A., Bernet R., Berninghoff D., Bernstein HC., Bertella C., Bertholet E., Bertolin A., Betancourt C., Betti F., Bettler MO., Bezshyiko I., Bhasin S., Bhom J., Bieker MS., Bifani S., Billoir P., Bizzeti A., Bjørn M., Blago MP., Blake T., Blanc F., Blusk S., Bobulska D., Bocci V., Boente Garcia O., Boettcher T., Boldyrev A., Bondar A., Bondar N., Borghi S., Borisyak M., Borsato M., Borsuk JT., Bowcock TJV., Bozzi C., Bradley MJ., Braun S., Brea Rodriguez A.
© 2020, The Author(s). A search is presented for the lepton flavour violating decay B+ → K+μ−τ+ using a sample of proton-proton collisions at centre-of-mass energies of 7, 8, and 13 TeV, collected with the LHCb detector and corresponding to a total integrated luminosity of 9 fb−1. The τ leptons are selected inclusively, primarily via decays with a single charged particle. The four-momentum of the τ lepton is determined by using B+ mesons from Bs2∗0→B+K− decays. No significant excess is observed, and an upper limit is set on the branching fraction ℬ(B+ → K+μ−τ+) < 3.9 × 10−5 at 90 % confidence level. The obtained limit is comparable to the world-best limit. [Figure not available: see fulltext.].