Measurement of branching fraction and CP asymmetries in B->D0(cp)K decays

TL;DR

This study measures branching fractions and CP asymmetries in B meson decays to D0 and K or pi, providing insights into CP violation using a large data sample from the BABAR experiment.

Contribution

First measurement of branching fraction ratios and CP asymmetries in B->D0(cp)K and pi decays with detailed CP eigenstate analysis.

Findings

Measured R_CP- = 0.81 ± 0.10 (stat) ± 0.05 (syst)

Measured R_CP+ = 1.07 ± 0.10 (stat) ± 0.04 (syst)

Measured A_CP- = -0.19 ± 0.12 (stat) ± 0.02 (syst)

Abstract

We present a preliminary study of $B^- \to D^0_{CP} \pi^-$ and $B^- \to D^0_{CP} K^-$ decays, with the $D^0_{CP}$ reconstructed in the CP-odd eigenstates $K_s \pi^0$, $K_s \omega$, in the CP-even eigenstates $K^+ K^-$, $\pi^+ \pi^-$, and in the (non-CP) flavor eigenstate $K^\mp \pi^\pm$. Using a sample of about 382 million Y(4S) decays into BBbar pairs, collected with the BABAR detector operating at the PEP-II asymmetric-energy B Factory at SLAC, we measure the ratios of the branching fractions R_CP+- and the direct CP asymmetries A_CP+-. The results are: R_CP- = 0.81 \pm 0.10 (stat) \pm 0.05 (syst) R_CP+ = 1.07 \pm 0.10 (stat) \pm 0.04 (syst) A_CP- = -0.19 \pm 0.12 (stat) \pm 0.02 (syst) A_CP+ = 0.35 \pm 0.09 (stat) \pm 0.05 (syst)