Measurement of the $CP$-violating phase $\ddot{I}{•}_s$ from $B_s^0\to J/\ddot{I}ˆ\ddot{I}{€}^{+}\ddot{I}{€}^{-}$ decays in 13 TeV $pp$ collisions

Abstract

Decays of $B_s^0$ and $\overline{B}{}_s^0$ mesons into $J/\ddot{I}ˆ\ddot{I}{€}^{+}\ddot{I}{€}^{-}$ 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 $\ddot{I}{•}_s=-0.057\pm 0.060\pm 0.011$ rad, the decay-width difference between the heavier mass $B_s^0$ eigenstate and the $B^0$ meson of $-0.050\pm 0.004\pm 0.004$ ps${}^{-1}$, and the $CP$-violating parameter $|\hat{I}»|=1.01_{-0.06}^{+0.08}\pm 0.03$, 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 $\ddot{I}{•}_s=0.002\pm 0.044\pm 0.012$ rad, and $|\hat{I}»|=0.949\pm 0.036\pm 0.019$.

All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2019-003.html