Journal Article

Search for the lepton flavour violating decay B+ → K+μ−τ+ using$$ {B}_{s2}^{\\ast 0} $$decays

Vorobyev, V., Chefdeville, M., Di Canto, A., Alexander, M., Jones, C. R., Durante, P., Gao, Y., Brossa Gonzalo, A., Yang, Z., Cardinale, R., Meinert, N., Mead, J. V., Barlow, R. J., Schmelling, M., Vázquez Sierra, C., Cai, H., Bedeschi, F., Swientek, K., Stefko, P., Millard, E., Pugatch, V., Ketel, T., Ekelhof, R., Bobulska, D., Ferro-Luzzi, M., Lefèvre, R., Zhang, S., Golubkov, D., Dalseno, J., Jawahery, A., Lai, A., Schneider, O., Rama, M., Bozzi, C., Carniti, P., Tran, M. T., Fontana, M., Straticiuc, M., Cenci, R., Ene, A., Smith, E., Zhou, X., Gibson, V., Mulder, M., Ramos Pernas, M., Jiang, F., Bezshyiko, Ia, Bertella, C., Tuning, N., Cobbledick, J. L., Kvaratskheliya, T., Morris, A. B., Williams, T., Carboni, G., Didenko, S., Calero Diaz, L., McNulty, R., Baldini, W., Ponce, S., Karacson, M., Nguyen-Mau, C., Pomery, G. J., Decamp, D., Hancock, T. H., Brea Rodriguez, A., Skidmore, N., Romanovskiy, V., Malecki, B., Cadeddu, S., Pappagallo, M., Kecke, M., Nanut, T., Marino, P., Materok, M., Merli, A., Epple, E., Dey, B., Lu, Y., Wiedner, D., Yu, J., Byczynski, W., Zarebski, K. A., Hatch, M., Maccolini, S., Mogini, A., Coelho, J. A. B., Yin, H., Quaglian

2020

Overview

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$$ {B}_{s2}^{\\ast 0}\\to {B}^{+}{K}^{-} $$B s 2 ∗ 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.