Measurement of the CP-violating phase ϕ<inf>s</inf> from B<inf>s</inf><sup>0</sup>→J/ψπ<sup>+</sup>π<sup>−</sup> decays in 13 TeV pp collisions
Aaij R., Abellán Beteta C., Adeva B., Adinolfi M., Aidala CA., Ajaltouni Z., Akar S., Albicocco P., Albrecht J., Alessio F., Alexander M., Alfonso Albero A., Alkhazov G., Alvarez Cartelle P., Alves AA., Amato S., Amhis Y., An L., Anderlini L., Andreassi G., Andreotti M., Andrews JE., Archilli F., Arnau Romeu J., Artamonov A., Artuso M., Arzymatov K., Aslanides E., Atzeni M., Audurier B., Bachmann S., Back JJ., Baker S., Balagura V., Baldini W., Baranov A., Barlow RJ., Barrand GC., Barsuk S., Barter W., Bartolini M., Baryshnikov F., Batozskaya V., Batsukh B., Battig A., Battista V., Bay A., Bedeschi F., Bediaga I., Beiter A., Bel LJ., Belin S., Beliy N., Bellee V., Belloli N., Belous K., Belyaev I., Bencivenni G., Ben-Haim E., Benson S., Beranek S., Berezhnoy A., Bernet R., Berninghoff D., Bertholet E., Bertolin A., Betancourt C., Betti F., Bettler MO., Bezshyiko I., Bhasin S., Bhom J., Bieker MS., Bifani S., Billoir P., Birnkraut A., Bizzeti A., Bjørn M., Blago MP., Blake T., Blanc F., Blusk S., Bobulska D., Bocci V., Boente Garcia O., Boettcher T., Bondar A., Bondar N., Borghi S., Borisyak M., Borsato M., Boubdir M., Bowcock TJV., Bozzi C., Braun S., Brodski M., Brodzicka J., Brossa Gonzalo A., Brundu D., Buchanan E.
© 2019 The Author Decays of Bs0 and B‾0s mesons into J/ψπ+π− final states are studied in a data sample corresponding to 1.9 fb−1 of integrated luminosity collected with the LHCb detector in 13 TeV pp collisions. A time-dependent amplitude analysis is used to determine the final-state resonance contributions, the CP-violating phase ϕs=−0.057±0.060±0.011 rad, the decay-width difference between the heavier mass Bs0 eigenstate and the B0 meson of −0.050±0.004±0.004 ps−1, and the CP-violating parameter |λ|=1.01−0.06+0.08±0.03, where the first uncertainty is statistical and the second systematic. These results are combined with previous LHCb measurements in the same decay channel using 7 TeV and 8 TeV pp collisions obtaining ϕs=0.002±0.044±0.012 rad, and |λ|=0.949±0.036±0.019.