Effective lifetime measurements in the $B_s^0\to K^{+}{K}^{-}$, $B^0\to K^{+}{\pi }^{-}$ and $B_s^0\to {\pi }^{+}{K}^{-}$ decays

Measurements of the effective lifetimes in the $B_{s}^{0} \rightarrow K^{+}K^{-}$,$B^{0} \rightarrow K^{+}\pi^{-}$and$B_{s}^{0} \rightarrow \pi^{+}K^{-}$decaysarepresentedusing$1.0~$\mathrm{f}{\mathrm{b}}^{-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 ${\tau }_{B_s^0\to K^{+}{K}^{-}}$ = $1.407\pm 0.016\pm 0.007\mathrm{p}\mathrm{s}$, ${\tau }_{B^0\to K^{+}{\pi }^{-}}$ = $1.524\pm 0.011\pm 0.004\mathrm{p}\mathrm{s}$, ${\tau }_{B_s^0\to {\pi }^{+}{K}^{-}}$ = $1.60\pm 0.06\pm 0.01\mathrm{p}\mathrm{s}$. This is the most precise determination to date of the effective lifetime in the $B_s^0\to K^{+}{K}^{-}$ decay and provides constraints on contributions from physics beyond the Standard Model to the $B_s^0$ mixing phase and the width difference $\mathrm{\Delta }{\mathrm{\Gamma }}_s$.