Analysis of Neutral B -Meson Decays into Two Muons
R. Aaij, Carlos Abellán Beteta, T. Ackernley, B. Adeva, M. Adinolfi, H. Afsharnia, C. Aidala, S. Aiola, Ziad Ajaltouni, S. Akar, J. Albrecht, F. Alessio, M. Alexander, A. Alfonso Albero, Zakariya Aliouche, Georgy Alkhazov, P. Álvarez Cartelle, S. Amato, Y. Amhis, Liupan An, L. Anderlini, A. Andreianov, M. Andreotti, F. Archilli, A. Artamonov, M. Artuso, Kenenbek Arzymatov, E. Aslanides, M. Atzeni, Benjamin Audurier, S. Bachmann, Marie Bachmayer, J. J. Back, P. Baladrón Rodríguez, V. Balagura, W. Baldini, Baptista Leite, Juan, R. J. Barlow, S. Barsuk, W. Barter, M. Bartolini, F. Baryshnikov, J. M. Basels, G. Bassi, B. Batsukh, A. Battig, A. Bay, M. Becker, F. Bedeschi, I. Bediaga, A. Beiter, V. Belavin, S. Belin, V. Bellée, K. Belous, I. Belov, I. Belyaev, G. Bencivenni, E. Ben-Haim, A. Berezhnoy, R. Bernet, D. Berninghoff, H. C. Bernstein, C. Bertella, A. Bertolin, C. Betancourt, F. Betti, Bezshyiko, Ia., Ia. Bezshyiko, S. Bhasin, J. Bhom, L. Bian, M. S. Bieker, S. Bifani, P. Billoir, M. Birch, F. C. R. Bishop, A. Bitadze, A. Bizzeti, Mikkel Bjørn, Michele Piero Blago, T. Blake, F. Blanc, S. Blusk, D. Bobulska, J. A. Boelhauve, Boente Garcia, Oscar, T. Boettcher, A. S. Boldyrev, A. Bondar, N. Bondar, S. Borghi, M. Borisyak, M. Borsato, J. T. Borsuk, Sonia Amina Bouchiba, T. J. V. Bowcock, A. Boyer, C. Bozzi, Matthew John Bradley
Abstract
Branching fraction and effective lifetime measurements of the rare decay B_{s}^{0}→μ^{+}μ^{-} and searches for the decays B^{0}→μ^{+}μ^{-} and B_{s}^{0}→μ^{+}μ^{-}γ are reported using proton-proton collision data collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV, corresponding to a luminosity of 9 fb^{-1}. The branching fraction B(B_{s}^{0}→μ^{+}μ^{-})=(3.09_{-0.43-0.11}^{+0.46+0.15})×10^{-9} and the effective lifetime τ(B_{s}^{0}→μ^{+}μ^{-})=2.07±0.29±0.03 ps are measured, where the first uncertainty is statistical and the second systematic. No significant signal for B^{0}→μ^{+}μ^{-} and B_{s}^{0}→μ^{+}μ^{-}γ decays is found and upper limits B(B^{0}→μ^{+}μ^{-})<2.6×10^{-10} and B(B_{s}^{0}→μ^{+}μ^{-}γ)<2.0×10^{-9} at the 95% C.L. are determined, where the latter is limited to the range m_{μμ}>4.9 GeV/c^{2}. The results are in agreement with the standard model expectations.