Measurement of $\phi_s$ and $\Delta\Gamma_s$ at LHCb

Abstract

Determination of the mixing-induced $C\!P$-violating phase $\phi_{s}$ and decay width difference $\Delta\Gamma_{s}$ in $\bar{b}\to\bar{c}c\bar{s}$ decays is one of the main goals of the LHCb experiment. Thanks to the precise prediction of the $\phi_{s}$ value within the Standard Model, it represents an excellent probe to search for new physics. The measurements of $\phi_{s}$ and $\Delta\Gamma_{s}$ at LHCb are reviewed including results from the 3.0~fb$^{-1}$ dataset accumulated during 2011-2012. Further measurement improvement is expected from the inclusion of results obtained using decay modes with smaller branching fraction.