Observation of CP violation in two-body B(s)0-meson decays to charged pions and kaons

Aaij, R.; Beteta, C. Abellan; Adeva, B.; Adinolfi, M.; Aidala, C. A.; Ajaltouni, Z.; Akar, S.; Albicocco, P.; Albrecht, J.; Alessio, F.; Alexander, M.; Albero, A. Alfonso; Alkhazov, G.; Cartelle, P. Alvarez; Alves, A. A., Jr.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Andreassi, G.; Andreotti, M.; Andrews, J. E.; Archilli, F.; d'Argent, P.; Romeu, J. Arnau; Artamonov, A.; Artuso, M.; Arzymatov, K.; Aslanides, E.; Atzeni, M.; Audurier, B.; Bachmann, S.; Back, J. J.; Baker, S.

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摘要

The time-dependent CP asymmetries of B-0 -> pi(+)pi(-) and B-s(0) -> K+K- decays are measured using a data sample of pp collisions corresponding to an integrated luminosity of 1.9 fb(-1), collected with the LHCb detector at a centre-of-mass energy of 13TeV. The results are @@@ C-pi pi = 0.311 +/- 0.045 +/- 0.015; @@@ S-pi pi = 0.706 +/- 0.042 +/- 0.013; @@@ C-KK = 0.164 +/- 0.034 +/- 0.014; @@@ S-KK = 0.123 +/- 0.034 +/- 0.015; @@@ A(KK)(Delta Gamma) = -0.83 +/- 0.05 +/- 0.09; @@@ where the first uncertainties are statistical and the second systematic. The same data sample is used to measure the time-integrated CP asymmetries of B-0 -> K + pi(-) and B-s(0) -> K-pi(+) decays and the results are @@@ AB(CP)(B0) = -0.0824 +/- 0.0033 +/- 0.0033; @@@ A(CP)(Bs0) = 0.236 +/- 0.013 +/- 0.011. @@@ All results are consistent with earlier measurements. A combination of LHCb measurements provides the first observation of time-dependent CP violation in B-s(0) decays.

关键词

B physics CP violation Flavor physics Hadron-Hadron scattering (experiments) Oscillation