Measurement of CP Violation in $B_s^0\to J/\psi \phi$ Decays Using the Full CDF Data Set

Book excerpt: We report on the final measurement of the CP-violating $B_s^0$ mixing phase $\beta_s^{J/[psi][phi]}$ in √s = 1.96 TeV proton-antiproton collisions collected with the Collider Detector at the Fermilab Tevatron collider. Using a sample corresponding to 9.6 fb-1 of integrated luminosity, we fit the decay-time evolution of $B_s^0$ → J/[psi] (→ [mu]+ [mu]-) [phi] (→ K+ K−) decays in which the b-quark content at production and the CP parity of the final state are identified. The interference of decays with and without mixing renders the $B_s^0$ mixing phase observable. The phase is determined to be -0.06