Search for the lepton-flavour violating decays \(B^+ \to K^+ {\mu}^{\pm} e^{\mp}\)

• Published in: arXiv.org 2019-09
• Main Authors: collaboration, LHCb, Andreotti, M, Aslanides, E, Bediaga, I, Bel, L J, Bertholet, E, Betancourt, C, Bezshyiko, Ia, Bifani, S, Borsuk, J T, Chatzikonstantinidis, G, Chekalina, V, Colombo, T, Costa Sobral, C M, Craik, D C, Da Silva, C L, Dean, C T, Demmer, M, Dettori, F, P Di Nezza, Ekelhof, R, Eklund, L, Fini, R A, V Franco Lima, Gallorini, S, J García Pardiñas, J Garra Tico, Ghez, Ph, Golutvin, A, Hancock, T H, Hasse, C, Hatch, M, Hicheur, A, Hunter, R J, Karodia, S, Ketel, T, Koppenburg, P, Kozeiha, M, Kunde, G J, Lane, J J, Leroy, O, Leverington, B, Liang, X, Luo, Y, R Ma, Maciuc, F, Mackowiak, P, Malinin, A, Martinelli, M, Morandin, M, Mukherjee, M, Newcombe, R, Nguyen, T D, Nguyen-Mau, C, Obraztsov, V, Onderwater, C J G, Owen, P, Pajero, T, Palutan, M, Perazzini, S, Perret, P, Poliakova, M, Quintana, B, Rama, M, M Ravonel Salzgeber, Reboud, M, Rotondo, M, Saitta, B, Satriano, C, Schneider, O, Sciascia, B, Sergi, A, Souza De Paula, B, Spradlin, P, Stagni, F, Stenyakin, O, Stocchi, A, Straticiuc, M, Straumann, U, Strokov, S, Sun, L, Szymanski, M, Tang, Z, Teubert, F, Tisserand, V, Tran, M T, Ukleja, A, Valat, S, P Vazquez Regueiro, Veltri, M, Vernet, M, Wang, Z, Wilkinson, M, Williams, I, Xiang, Z, Xiao, D, Xing, H, M Xu, Yin, H, Yuan, X
• Format: Article
• Language: English
• Subjects: Confidence intervals; Decay; Flavors; Large Hadron Collider; Leptons; Luminosity; Particle collisions; Protons
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1909.01010

A search for the lepton-flavour violating decays \(B^+ \to K^+ {\mu}^{\pm} e^{\mp}\) is performed using a sample of proton-proton collision data, collected with the LHCb experiment at centre-of-mass energies of \(7\) and \(8~{\rm TeV}\) and corresponding to an integrated luminosity of 3\(\rm~fb^{-1}\). No significant signal is observed, and upper limits on the branching fractions are set as \(\mathcal{B}(B^+ \to K^+ {\mu}^- e^+) < 7.0~(9.5) \times 10^{-9}\) and \(\mathcal{B}(B^+ \to K^+ {\mu}^+ e^-) < 6.4~(8.8) \times 10^{-9}\) at 90 (95) % confidence level. The results improve the current best limits on these decays by more than one order of magnitude.