$B^0_s \to J/\psi\phi$ LHC Review

Analysis of the angular distributions of the final products of the B^0_sto Jpsi phi decay chain allows the determination of B^0_s mixing parameters, in particular the width difference Delta Gamma_s which is at present not precisely measured. It also allows measurement of the CP-violating phase phi_s of the B^0_s system, which is expected to be very small (0.03) in the Standard Model but might show large non-SM enhancements. The high production rate of B^0_s mesons at the LHC will permit precise measurements of these quantities; the performances of the three LHC experiments with a B physics programme (ATLAS, CMS and LHCb) in the reconstruction and analysis of this decay will be presented.