# {First Flavor-Tagged Determination of Bounds on Mixing- Induced CP Violation in Bs -> J/psi phi Decays}

This Letter describes the first determination of bounds on the CP-violation parameter 2betas using Bs0 decays in which the flavor of the bottom meson at production is identified. The result is based on approximately 2000 Bs0-->J/psiphi decays reconstructed in a 1.35 fb-1 data sample collected with the CDF II detector using $p\bar{p}$ collisions produced at the Fermilab Tevatron. We report confidence regions in the two-dimensional space of 2betas and the decay-width difference DeltaGamma. Assuming the standard model predictions of 2betas and DeltaGamma, the probability of a deviation as large as the level of the observed data is 15%, corresponding to 1.5 Gaussian standard deviations.

### Cited Authors

• Aaltonen, ; T, ; others,

• 2008

### Published In

• Phys. Rev. Lett.

• 100 /

• 161802 -

• 18518184