New results on CP violation in $B^0_s$ Mixing from LHCb using the full 1 fb$^{-1}$ of data from the 2011 LHC run (including measurements of $\phi_s$ and $\Delta \Gamma_s$)

The CP violating phase $\phi_s$ can be measured using the interference between the direct and mixed $B^0_s$ decays to a CP eigenstate. Using a sample of about 21200 $B^0_s \to J/\psi \phi$ and 7421 $B^0_s \to J/\psi \pi^+\pi^-$ events we measure the phase $\phi_s$ , the mean decay width difference $\Delta \Gamma_s$ and the average decay width $\Gamma_s$ . These data were collected from 1 fb$^{−1}$ of $pp$ collisions collected during the 2011 LHC run at a centre of mass energy of $\sqrt{s}$ = 7 TeV. From the $ J/\psi \phi$ data we find $\Gamma_s = 0.6580 \pm 0.0054 \rm{(stat)} \pm 0.0066\rm{(syst)}$ ps$^{−1}$ , and $\Delta \Gamma_s = 0.116 \pm 0.018 \rm{(stat)} \pm .006 \rm{(syst)}$ ps$^{−1}$ . From the combined $ J/\psi \phi$ and $ J/\psi \pi^+\pi^-$ data we find $\phi_s = −0.002 \pm 0.083 \pm 0.027$ rad.