Rates, Polarizations, and Asymmetries in Charmless Vector-Vector B Decays

TL;DR

This paper reports measurements of branching fractions, polarization, and CP violation in charmless vector-vector B decays using a large BABAR dataset, including new decay observations and asymmetry measurements.

Contribution

It provides the first measurements of branching fractions, polarization, and CP asymmetries for several charmless vector-vector B decays, including new decay modes.

Findings

Measured branching fractions for B decays to phiK* and rhoK* modes.

Determined longitudinal polarization fractions in these decays.

Found no significant direct CP violation in the studied decays.

Abstract

With a sample of approximately 89 million BBbar pairs collected with the BABAR detector, we measure branching fractions, determine the degree of longitudinal polarization, and search for direct CP violation in the decays B0=>phiK*0 and B+=>phiK*+. We perform a search for other charmless vector-vector B decays involving rho and K*(892) resonances and observe the decays B+=>rho0K*+ and B+=>rho0rho+. The branching fractions are measured to be BR(phiK*0)=(11.1^{+1.3}_{-1.2}\pm 1.1)10^{-6}, BR(phiK*+)=(12.1^{+2.1}_{-1.9}\pm 1.5)10^{-6}, BR(rho0K*+)=(7.7^{+2.1}_{-2.0}\pm 1.4)10^{-6}, and BR(rho0rho+)=(9.9^{+2.6}_{-2.5}\pm 2.5)10^{-6}. The longitudinal polarization fractions are measured to be GammaL/Gamma(phiK*0)=0.65\pm 0.07\pm 0.04 and GammaL/Gamma(phiK*+)=0.46\pm 0.12\pm 0.05. We measure the charge asymmetries: ACP(phiK*0)=+0.04\pm 0.12\pm 0.02 and ACP(phiK*+)=+0.16\pm 0.17\pm 0.04.