Measurement of Polarization and Search for CP-Violation in $B_s^0\to \varphi \varphi$ Decays

Abstract

We present the first measurement of polarization and CP-violating asymmetries in $B_s^0$ decays into two light vector mesons, $B_s^0\to \varphi \varphi$, and an improved determination of its branching ratio using 295 decays reconstructed in a data sample corresponding to 2.9 fb^-1 of integrated luminosity collected by the CDF experiment at the Fermilab Tevatron collider. The fraction of longitudinal polarization is determined to be $\text{fL}=0.348\pm 0.041(\mathrm{stat})\pm 0.021(\mathrm{syst})$, and the branching ratio $BR($B_s^0 \to \phi\phi$)=[2.32\pm 0.18(\mathrm{stat})\pm 0.82(\mathrm{syst})]\times 10^{-5}$. Asymmetries of decay angle distributions sensitive to \CP\ violation are measured to be $A_u=-0.007\pm 0.064\text{stat}\pm 0.018\text{syst}$ and $A_v=-0.120\pm 0.064stat\pm 0.016\text{syst}$.

Comments: published version, sign corrected in eq. 2