Measurements Of Direct CP Asymmetry Research Articles

Recent studies of CP violation at the Tevatron

In this paper the most recent Tevatron results concerning CP violation are reviewed. These are the measurements of direct CP asymmetry in the charmless two-body decays of B0, B0s and Ab (performed by CDF), CP asymmetry in B+ → J/ψK* (performed by D0), the flavor-tagged measurement of B0s semileptonic asymmetry, assl and the measurement of bs in the decay B0s→ J/ψϕ (performed by CDF and D0).

B→ππ decays

The branching ratios and CP asymmetries of $B\to \pi\pi$ decays measured in B factory experiments indicate a large ratio of color-suppressed ($C$) to color-allowed ($T$) tree contributions and a large relative phase between the tree and penguin amplitude. In this talk, I would like to report on a recent analysis to see whether the large $C/T$ ratio can be explained within the QCD based model with i) a large contribution from the annihilation terms or with ii) large final-state-interaction phase between two different isospin amplitudes. We show that the current experimental data do not exclude either possibility but we may be able to distinguish these two effects in future measurements of direct CP asymmetry in $B\to \pi^{0}\pi^{0}$ decay.

Charmless B decays at CDF

In this paper I review the most recent CDF II results in the field of charmless B decays: the measurement of the relative branching fractions of B 0 and B s 0 → h + h ′ − decays, the direct CP asymmetry in the B 0 → K + π − decay, the limits on the Λ b 0 → h + h ′ − branching fractions, the first evidence of B s 0 → ϕ ϕ decay and the measurement of direct CP asymmetry in the B + → ϕ K + decay.

CP violation and CKM measurements in Bottom and Charm decays at CDF

We present preliminary measurements of branching ratios and CP asymmetries in 5 charmless decay modes of the B mesons and precise measurement of direct CP asymmetry in Cabibbo-suppressed charm decays. We used 180pb−1 of the hadronic-b data stream of CDF's Tevatron Run2. The decay mode B s → ϕ ϕ has been observed for the first time, with a branching fraction of ( 1.4 ± 0.6 ± 0.2 ± 0.5 ) × 10 −5 . We also present the first measurement of the branching fraction B ( B s → K + K − ) = ( 3.56 ± 0.57 ± 0.50 ± 0.43 ) × 10 −5 .