Effective lifetime measurements in the $B_{s}^{0} \rightarrow   K^{+}K^{-}$, $B^{0} \rightarrow K^{+}\pi^{-}$ and $B_{s}^{0} \rightarrow   \pi^{+}K^{-}$ decays
  Measurements of the effective lifetimes in the $B_{s}^{0} \rightarrow K^{+}K^{-}$, $B^{0} \rightarrow K^{+}\pi^{-}$ and $B_{s}^{0} \rightarrow \pi^{+}K^{-}$ decays are presented using $1.0~\mathrm{fb^{-1}}$ of $pp$ collision data collected at a centre-of-mass energy of 7 TeV by the LHCb experiment. The analysis uses a data-driven approach to correct for the decay time acceptance. The measured effective lifetimes are   $\tau_{B_{s}^{0} \rightarrow K^{+}K^{-}}$ = $1.407~\pm~0.016~\pm~0.007~\mathrm{ps}$,   $\tau_{B^{0} \rightarrow K^{+}\pi^{-}}$ = $1.524~\pm~0.011~\pm~0.004~\mathrm{ps}$,   $\tau_{B_{s}^{0} \rightarrow \pi^{+}K^{-}}$ = $1.60~\pm~0.06~\pm~0.01~\mathrm{ps}$.   This is the most precise determination to date of the effective lifetime in the $B_{s}^{0} \rightarrow K^{+}K^{-}$ decay and provides constraints on contributions from physics beyond the Standard Model to the $B_{s}^{0}$ mixing phase and the width difference $\Delta\Gamma_{s}$. 
R. Aaij, B. Adeva, M. Adinolfi, A. Affolder, Z. Ajaltouni, J.   Albrecht, F. Alessio, M. Alexander, S. Ali, G. Alkhazov, P. ...
hep-ex