Measurement of the charge asymmetry in $B^{\pm}\rightarrow \phi K^{\pm}$ and search for $B^{\pm}\rightarrow \phi \pi^{\pm}$ decays

• Published in: Physics letters. B Vol. 728; pp. 85 - 94
• Main Authors: Aaij, R., Amhis, Y., Barsuk, S., Callot, O., He, J., Kochebina, O., Lefrançois, J., Machefert, F., Martin Sanchez, A., Nicol, M., Robbe, P., Schune, M.-H., Teklishyn, M., Vallier, A., Viaud, B., Ben-Haim, E., Benayoun, M., David, P., del Buono, L., Martens, A., Milanes, D.A., Polci, F., Ajaltouni, Ziad Zj, Baalouch, M., Cogneras, E., Deschamps, O., El Rifai, I., Grabalosa Gándara, M., Henrard, Pierre, Hoballah, M., Lefèvre, R., Li Gioi, L., Maratas, J., Monteil, S., Niess, V., Perret, Pascal, Roa Romero, Diego Alejandro, Adrover, C., Aslanides, E., Cogan, J., Kanso, W., Legac, R., Leroy, O., Mancinelli, G., Maurice, E., Mordà, A., Perrin-Terrin, M., Sapunov, M., Serrano, J., Tsaregorodtsev, A., de Bonis, I., Decamp, D., Déléage, N., Ghez, Ph, Lees, J.-P., Machikhiliyan, I.V., Minard, M.-N., Pietrzyk, B., Qian, W., t'Jampens, S., Tisserand, V., Tournefier, E.
• Format: Journal Article
• Language: English
• Published: Elsevier 2014
• Subjects: High Energy Physics - Experiment; Physics
• ISSN: 0370-2693
• DOI: 10.1016/j.physletb.2013.11.036

The \CP-violating charge asymmetry in $B^{\pm}\rightarrow \phi K^{\pm}$ decays is measured in a sample of $pp$ collisions at 7 TeV centre-of-mass energy, corresponding to an integrated luminosity of 1.0 fb$^{-1}$ collected by the LHCb experiment. The result is $\mathcal{A}_{CP}(B^{\pm}\rightarrow \phi K^{\pm}) = \rm 0.022\pm 0.021 \pm 0.009$, where the first uncertainty is statistical and the second systematic. In addition, a search for the $B^{\pm}\rightarrow \phi \pi^{\pm}$ decay mode is performed, using the $B^{\pm}\rightarrow \phi K^{\pm}$ decay rate for normalization. An upper limit on the branching fraction $\mathcal{B}(B^{\pm}\rightarrow \phi \pi^{\pm})< 1.5\times 10^{-7}$ is set at 90% confidence level.