Measurement of the $B_s^0to J/psi K_S^0$ branching fraction

The $B_s^0to J/psi K_S^0$ branching fraction is measured in a data sample corresponding to 0.41$fb^{-1}$ of integrated luminosity collected with the LHCb detector at the LHC. This channel is sensitive to the penguin contributions affecting the sin2$beta$ measurement from $B^0to J/psi K_S^0$ The time-integrated branching fraction is measured to be $BF(B_s^0to J/psi K_S^0)=(1.83pm0.28)times10^{-5}$. This is the most precise measurement to date.