$\phi_{s}$ status and prospects at LHCb

Abstract

Recent measurements of the time-dependent CP violation by the LHCb experiment are presented. The decays of B s mesons to J/ψK + K − and J/ψπ + π − final states are used to measure the CPviolating phase φ s in tree-dominated transitions, while B 0 s → (K + π −)(K − π +) and B 0 s → φ φ decay modes are used to measure the CP-violating phases φ sdd s and φ sss s , which arise in penguindominated decays. The most recent status of the analyses of the four decay modes is summarised.