Measurement of CP violation and the Bs0 meson decay width difference with Bs0→J/ψK+K- and Bs0→J/ψπ +π - Decays

R. Aaij, C. Abellan Beteta, 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. AndreassenR. B. Appleby, O. Aquines Gutierrez, F. Archilli, A. Artamonov, M. Artuso, E. Aslanides, G. Auriemma, 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, M. Benayoun, 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, I. Burducea, A. Bursche, G. Busetto, J. Buytaert, S. Cadeddu, O. Callot, M. Calvi, M. Calvo Gomez, A. Camboni, P. Campana, A. Carbone, G. Carboni, R. Cardinale, A. Cardini, H. Carranza-Mejia, L. Carson, K. Carvalho Akiba, G. Casse

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The time-dependent CP asymmetry in Bs0→J/ψK +K - decays is measured using pp collision data at √s=7 TeV, corresponding to an integrated luminosity of 1.0 fb -1, collected with the LHCb detector. The decay-time distribution is characterized by the decay widths Γ L and Γ H of the light and heavy mass eigenstates of the Bs0-B̄s0 system and by a CP-violating phase s. In a sample of 27 617 Bs0→J/ψK +K - decays, where the dominant contribution comes from Bs0→J/ψ decays, these parameters are measured to be s=0.07±0.09(stat) ±0.01(syst) rad, Γ s≡(Γ LH)/2=0.663±0.005(stat)±0.006(syst) ps -1, and ΔΓ s≡Γ LH=0. 100±0.016(stat)±0.003(syst) ps -1, corresponding to the single most precise determination of s, ΔΓ s, and Γ s. The result of performing a combined analysis with Bs0→J/ψπ +π - decays gives s=0.01±0.07(stat)±0.01(syst) rad, Γ s= 0.661±0.004(stat)±0.006(syst) ps -1, and ΔΓ s=0.106±0.011(stat)±0.007(syst) ps -1. All measurements are in agreement with the Standard Model predictions.

Original languageEnglish
Article number112010
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Issue number11
Publication statusPublished - 21 Jun 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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