PT Journal AU LHCb Collaboration (Aaij, Rea Martinez-Vidal, F Oyanguren, A Ruiz Valls, P Sanchez Mayordomo, C TI Observation of the B (s) (0) -> J/psi phi phi decay SO Journal of High Energy Physics JI J. High Energy Phys. PY 2016 BP 040 EP 18pp VL 03 IS 3 DI 10.1007/JHEP03(2016)040 LA English DE B physics; Branching fraction; Hadron-Hadron scattering; QCD; Spectroscopy AB The B (s) (0) -> J/psi phi phi decay is observed in pp collision data corresponding to an integrated luminosity of 3 fb(-1) recorded by the LHCb detector at centre-of-mass energies of 7 TeV and 8 TeV. This is the first observation of this decay channel, with a statistical significance of 15 standard deviations. The mass of the B (s) (0) meson is measured to be 5367.08 +/- 0.38 +/- 0.15 MeV/c(2). The branching fraction ratio B[B(s)(0) -> J/psi phi phi]/B[B(s)(0) -> J/psi phi] is measured to be 0.0115 +/- 0.0012 (- 0.0009) (+ 0.0005) . In both cases, the first uncertainty is statistical and the second is systematic. No evidence for non-resonant B(s)(0) -> J/psi phi K (+) K (-) or B(s)(0) -> J/psi K (+) K (-) K (+) K (-) decays is found. ER