Observation of the decay B s 0  → η c ϕ and evidence for B s 0  → η c π + π

• Published in: The journal of high energy physics Vol. 2017; no. 7; pp. 1 - 33
• Main Authors: Aaij, R., Adeva, B., Adinolfi, M., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Ali, S., Alkhazov, G., Alvarez Cartelle, P., Alves, A. A., Amato, S., Amerio, S., Amhis, Y., An, L., Anderlini, L., Andreassi, G., Andreotti, M., Andrews, J. E., Appleby, R. B., Archilli, F., d’Argent, P., Arnau Romeu, J., Artamonov, A., Artuso, M., Aslanides, E., Auriemma, G., Baalouch, M., Babuschkin, I., Bachmann, S., Back, J. J., Badalov, A., Baesso, C., Baker, S., Balagura, V., Baldini, W., Barlow, R. J., Barschel, C., Barsuk, S., Barter, W., Baryshnikov, F., Baszczyk, M., Batozskaya, V., Batsukh, B., Battista, V., Bay, A., Beaucourt, L., Beddow, J., Bedeschi, F., Bediaga, I., Bel, L. J., Bellee, V., Belloli, N., Belous, K., Belyaev, I., Ben-Haim, E., Bencivenni, G., Benson, S., Berezhnoy, A., Bernet, R., Bertolin, A., Betancourt, C., Betti, F., Bettler, M.-O., van Beuzekom, M., Bezshyiko, Ia, Bifani, S., Billoir, P., Bird, T., Birnkraut, A., Bitadze, A., Bizzeti, A., Blake, T., Blanc, F., Blouw, J., Blusk, S., Bocci, V., Boettcher, T., Bondar, A., Bondar, N., Bonivento, W., Bordyuzhin, I., Borgheresi, A., Borghi, S., Borisyak, M., Borsato, M., Bossu, F., Boubdir, M., Bowcock, T. J. V., Bowen, E., Bozzi, C., Braun, S., Britsch, M., Britton, T., Brodzicka, J., Buchanan, E., Burr, C., Bursche, A., Buytaert, J.
• Format: Journal Article
• Language: English
• Published: SpringerOpen 01.07.2017
• Subjects: B physics; Branching fraction; Flavor physics; Hadron-Hadron scattering (experiments)
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP07(2017)021

Abstract A study of B s 0  → η c ϕ and B s 0  → η c π + π − decays is performed using pp collision data corresponding to an integrated luminosity of 3.0 fb−1, collected with the LHCb detector in Run 1 of the LHC. The observation of the decay B s 0  → η c ϕ is reported, where the η c meson is reconstructed in the p p ¯ $$ p\overline{p} $$ , K + K − π + π −, π + π − π + π − and K + K − K + K − decay modes and the ϕ(1020) in the K + K − decay mode. The decay B s 0  → J/ψϕ is used as a normalisation channel. Evidence is also reported for the decay B s 0  → η c π + π −, where the η c meson is reconstructed in the p p ¯ $$ p\overline{p} $$ decay mode, using the decay B s 0  → J/ψπ + π − as a normalisation channel. The measured branching fractions are ℬ B s 0 → η c ϕ = 5.01 ± 0.53 ± 0.27 ± 0.63 × 10 − 4 , ℬ B s 0 → η c π + π − = 1.76 ± 0.59 ± 0.12 ± 0.29 × 10 − 4 , $$ \begin{array}{l}\mathrm{\mathcal{B}}\left({B}_s^0\to {\eta}_c\phi \right)=\left(5.01\pm 0.53\pm 0.27\pm 0.63\right)\times {10}^{-4},\hfill \\ {}\mathrm{\mathcal{B}}\left({B}_s^0\to {\eta}_c{\pi}^{+}{\pi}^{-}\right)=\left(1.76\pm 0.59\pm 0.12\pm 0.29\right)\times {10}^{-4},\hfill \end{array} $$ where in each case the first uncertainty is statistical, the second systematic and the third uncertainty is due to the limited knowledge of the external branching fractions.