We present a search for physics beyond the standard model (SM) through a measurement of the violation of the charge-parity (CP) symmetry in two decays of the Bs meson using data collected by the Collider Detector at Fermilab (CDF)
in proton-antiproton collisions at the center-of-mass energy of 1.96 Tev. We exploit the decays Bs->Jpsi (->mu mu) phi(-> KK) and Bs -> phi(-> KK) phi(-> KK), for which the SM accurately predicts very small or vanishing CP violation; both decay modes are very sensitive to new sources of CP violation expected in a broad class of SM extensions. We analyze the time-dependent CP asymmetry of the Bs->Jpsi phi decays collected in the full CDF Run II dataset for providing the final measurement of the Bs-antiBs mixing phase, 2*betas, and we present the first measurement of CP violation in Bs -> Phi Phi decays, through the determination of two time-integrated CP asymmetries, Av and Au, using an original method developed in this work.
We find: -0.06< betas<0.30 at the 68% confidence level;
Av=(-12.0 +/-6.4(stat) +/- 1.6(syst))%; and
Au=(-0.7 +/-6.4(stat) +/- 1.8(syst))%.
In addition, we provide measurements of the
decay width difference between the light and heavy
mass eigenstates of the Bs meson, DeltaGamma_s=0.068 +/- 0.026(stat) +/- 0.009(syst) ps^{-1}; and of their mean lifetime, tau_s=1.528 +/- 0.019(stat) +/- 0.009(syst) ps.
All results are among the most precise determinations from a single experiment and exhibit an excellent agreement with the SM predictions. They have been published in two letters in Physical Review.
