First observation of B̄0→J/ψK+K - and search for B̄0→J/ψφ decays

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

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28 Citations (Scopus)


The first observation of the B ̄0→J/ψK +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 ̄0→J/ψK +K -)=(2.53±0.31±0.19)×10 -6, where the first uncertainty is statistical and the second is systematic. An amplitude analysis of the final state in the B ̄0→J/ψK +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 ̄0→J/ψa 0(980),a 0(980)→K +K -)=(4.70±3.31±0. 72)×10 -7, yielding an upper limit of B(B ̄0→J/ψa 0(980),a 0(980)→K +K -)<9.0×10 -7 at 90% confidence level. No evidence of the resonant decay B ̄0→J/ψφ is found, and an upper limit on its branching fraction is set to be B(B ̄0→J/ψφ)<1.9×10 -7 at 90% confidence level.

Original languageEnglish
Article number072005
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Issue number7
Publication statusPublished - 14 Oct 2013
Externally publishedYes

Bibliographical note

Copyright 2013 Elsevier B.V., All rights reserved.

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Physics and Astronomy (miscellaneous)


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