Measurements of the B+, B-0, B-s(0) meson and Lambda(0)(b) baryon lifetimes

R. Aaij, B. Adeva, M. Adinolfi, 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, M. Andreotti, 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, A. Badalov, V. Balagura, W. Baldini, R. J. Barlow, C. Barschel, S. Barsuk, W. Barter, V. Batozskaya, Th. Bauer, A. Bay, J. Beddow, F. Bedeschi, Laurence Carson, P. E. L. Clarke, G. A. Cowan, Daniel Craik, S. Eisenhardt, F. Muheim, M. Needham, S. Playfer, LHCb Collaboration

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Measurements of b-hadron lifetimes are reported using p p collision data, corresponding to an integrated luminosity of 1.0 fb(-1), collected by the LHCb detector at a centre-of-mass energy of 7 TeV. Using the exclusive decays B+ -> J/psi K+, B-0 -> J/psi K* (892)(0), B-0 -> J/K-s(0), Lambda(0)(b) -> J/psi Lambda and B-s(0) -> J/psi phi the average decay times in these modes are measured to be

tau(B+) -> J/psi K+ = 1.637 +/- 0.004 +/- 0.003 p s,

tau(B0) -> J/psi K*(0) = 1.524 +/- 0.006 +/- 0.004 p s,

tau(0)(B) -> J/psi K-s(0) = 1.499 +/- 0.013 +/- 0.005 ps,

tau Lambda(0)(b) -> J/psi Lambda = 1.415 +/- 0.027 +/- 0.006 ps,

tau(0)(Bs) -> J/psi phi = 1.480 +/- 0.011 +/- 0.005 ps,

where the first uncertainty is statistical and the second is systematic. These represent the most precise lifetime measurements in these decay modes. In addition, ratios of these lifetimes, and the ratio of the decay-width difference, Delta Gamma(d), to the average width, Gamma(d), in the B-0 system, Delta Gamma(d)/Gamma(d) = -0.044 +/- 0.025 +/- 0.011, are reported. All quantities are found to be consistent with Standard Model expectations.

Original languageEnglish
Article number114
Number of pages26
JournalJournal of High Energy Physics
Issue number4
Publication statusPublished - 16 Apr 2014


  • Lifetime
  • Hadron-Hadron Scattering
  • B physics
  • Flavor physics
  • QCD
  • TOOL

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