Journal Article

First observation of the decay$ B_c^{+}\\to {J \\left/ {{\\psi {K^{+}}}} \\right.}

Wicht, J., Vorobyev, V., Di Canto, A., Hicheur, A., Popov, D., Alexander, M., De Cian, M., Deschamps, O., Wang, J., Jones, C. R., Gao, Y., Trigo, E. Perez, Alvarez, A. Pazos, Yang, Z., Cardinale, R., Lees, J.-P., Barlow, R. J., Nikodem, T., Ilten, P., Moran, D., Schmelling, M., Lanfranchi, G., Matev, R., Jans, E., Bedeschi, F., Okhrimenko, O., Haines, S. C., Henrard, P., Pugatch, V., Torr, N., Bonivento, W., Ketel, T., Ekelhof, R., Ferro-Luzzi, M., Oldeman, R., Hussain, N., Lefèvre, R., Golubkov, D., Shevchenko, V., Valls, P. Ruiz, Morello, M. J., Jawahery, A., Lai, A., Schneider, O., Cardoso, L. A. Granado, Soler, F. J. P., Bozzi, C., Joram, C., van den Brand, J., Tran, M. T., Sciubba, A., Fontana, M., Wu, S., Straticiuc, M., Smith, E., Egorychev, V., van Eijk, D., Gibson, V., Tisserand, V., Storaci, B., Soomro, F., Tuning, N., Kvaratskheliya, T., Luo, H., Altarelli, M. Pepe, Carboni, G., McNulty, R., Vidal, X. Cid, Leroy, O., Machikhiliyan, I. V., Baldini, W., Lesiak, T., Barschel, C., Karacson, M., Nguyen-Mau, C., Decamp, D., Guz, Yu, Rodrigues, E., Souza, D., Cadeddu, S., Pappagallo, M., Witek, M., Cowan, G. A., Shcheglov, Y., Voong, D., La Thi, V.

2013

Overview

The decay$ B_c^{+}\\to {J \\left/ {{\\psi {K^{+}}} \\right.} $is observed for the first time using a data sample, corresponding to an integrated luminosity of 1.0 fb −1 , collected by the LHCb experiment in pp collisions at a centre-of-mass energy of 7 TeV. A yield of 46 ± 12 events is reported, with a significance of 5.0 standard deviations. The ratio of the branching fraction of$ B_c^{+}\\to {J \\left/ {{\\psi {K^{+}}} \\right.} $to that of$ B_c^{+}\\to {J \\left/ {{\\psi {\\pi^{+}}} \\right.} $is measured to be 0.069 ± 0.019 ± 0.005, where the first uncertainty is statistical and the second is systematic.