First observation of (B)over-bar(0) -> J/psi K+K- and search for (B)over-bar(0) -> J/psi phi decays

Aaij, R.; Adeva, B.; Adinolfi, M.; Adrover, C.; Affolder, A.; Ajaltouni, Z.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A. Jr.; Amato, S.; Amerio, S.; Amhis, Y.; Anderlini, L.; Anderson, J.; Andreassen, R.; Andrews, J. E.; Appleby, R. B.; Gutierrez, O. Aquines; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Baesso, C.; Balagura, V.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Bauer, Th.; Bay, A.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Belogurov, S.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bettler, M.-O.; Van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Bizzeti, A.; Bjornstad, P. M.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Brambach, T.; Van Den Brand, J.; Bressieux, J.; Brett, D.; Britsch, M.; Britton, T.; Brook, N. H.; Brown, H.; Bursche, A.; Busetto, G.; Buytaert, J.; Cadeddu, S.; Callot, O.; Calvi, M.; Calvo Gomez, M.; Camboni, A.; Campana, P.; Campora Perez, D.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carranza-Mejia, H.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Cassina, L.; Castillo Garcia, L.; Cattaneo, M.; et al.

doi:10.1103/PhysRevD.88.072005

research article

First observation of (B)over-bar(0) -> J/psi K+K- and search for (B)over-bar(0) -> J/psi phi decays

Aaij, R.

•

Adeva, B.

•

Adinolfi, M.

2013

Physical Review D [1970-2015]

The first observation of the (B) over bar (0) -> J/psi K+K- decay is presented with a data sample corresponding to an integrated luminosity of 1.0 fb(-1) of pp collisions at a center-of-mass energy of 7 TeV collected with the LHCb detector. The branching fraction is measured to be B((B) over bar (0) -> J/psi K+K-) = (2.53 +/- 0.31 +/- 0.19) x 10(-6), where the first uncertainty is statistical and the second is systematic. An amplitude analysis of the final state in the (B) over bar (0) -> J/psi K+K- decay is performed to separate resonant and nonresonant contributions in the K+K- spectrum. Evidence of the a(0)(980) resonance is reported with statistical significance of 3.9 standard deviations. The corresponding product branching fraction is measured to be B((B) over bar (0) -> J/psi a(0)(980), a(0)(980) -> K+K-) = (4.70 +/- 3.31 +/- 0.72) x 10(-7), yielding an upper limit of B((B) over bar (0) -> J/psi a(0)(980), a(0)(980) -> K+K-) < 9.0 x 10(-7) at 90% confidence level. No evidence of the resonant decay <(B)over bar>(0) J/psi phi is found, and an upper limit on its branching fraction is set to be B((B) over bar (0) -> J/psi phi) <1.9 x 10(-7) at 90% confidence level.