Observation of the rare B0s→μ+μ− decay from the combined analysis of CMS and LHCb data

V. Khachatryan , Y. Amhis (1) , S. Barsuk (1) , M. Borsato (1) , O. Kochebina (1) , J. Lefrançois (1) , F. Machefert (1) , A. Martin Sanchez (1) , M. Nicol (1) , P. Robbe (1) , M.-H. Schune (1) , M. Teklishyn (1) , A. Vallier (1) , B. Viaud (1) , S. Beauceron (2) , N. Beaupere (2) , G. Boudoul E. Bouvier , S. Brochet (2) , C.A. Carrillo Montoya (2) , J. Chasserat (2) , R. Chierici (2) , D. Contardo (2) , P. Depasse (2) , H. El Mamouni (2) , J. Fan (2) , J. Fay (2) , S. Gascon (2) , M. Gouzevitch (2) , B. Ille (2) , T. Kurca (2) , M. Lethuillier (2) , L. Mirabito (2) , S. Perries (2) , J.D. Ruiz Alvarez (2) , D. Sabes (2) , L. Sgandurra (2) , V. Sordini (2) , M. Vander Donckt (2) , P. Verdier (2) , S. Viret (2) , H. Xiao (2) , S. Gadrat (3) , S. Akar (4) , E. Aslanides (4) , J. Cogan (4) , W. Kanso (4) , R. Legac (4) , O. Leroy (4) , G. Mancinelli (4) , A. Mordà (4) , J. Serrano (4) , A. Tsaregorodtsev (4) , L. Beaucourt (5) , M. Chefdeville (5) , D. Decamp (5) , N. Déléage (5) , Ph. Ghez (5) , J.-P. Lees (5) , J.-F. Marchand (5) , M.-N. Minard (5) , B. Pietrzyk (5) , W. Qian (5) , S. t'Jampens (5) , V. Tisserand (5) , E. Tournefier (5)

1 LAL - Laboratoire de l'Accélérateur Linéaire
2 IPNL - Institut de Physique Nucléaire de Lyon
3 CC-IN2P3 - Centre de Calcul de l'IN2P3
4 CPPM - Centre de Physique des Particules de Marseille
5 LAPP - Laboratoire d'Annecy de Physique des Particules

A joint measurement is presented of the branching fractions B0s→μ+μ− and B0→μ+μ− in proton-proton collisions at the LHC by the CMS and LHCb experiments. The data samples were collected in 2011 at a centre-of-mass energy of 7 TeV, and in 2012 at 8 TeV. The combined analysis produces the first observation of the B0s→μ+μ− decay, with a statistical significance exceeding six standard deviations, and the best measurement of its branching fraction so far, and three standard deviation evidence for the B0→μ+μ− decay. The measurements are statistically compatible with SM predictions and impose stringent constraints on several theories beyond the SM.

Domaines: Physique des Hautes Energies - Expérience [hep-ex]; Physique des Hautes Energies - Phénoménologie [hep-ph]

V. Khachatryan, Y. Amhis, S. Barsuk, M. Borsato, O. Kochebina, et al.. Observation of the rare B0s→μ+μ− decay from the combined analysis of CMS and LHCb data. Nature, 2015, 522 (7554), pp.68-74. ⟨10.1038/nature14474⟩. ⟨in2p3-01084204⟩