Measurements of the branching fractions and CP-asymmetries of B- --> D0_(CP) K- decays

TL;DR

This paper measures branching fractions and CP asymmetries in B- --> D0_(CP) K- decays, providing insights into CP violation and the CKM angle gamma using a large data sample from the BABAR experiment.

Contribution

First measurement of CP asymmetries and branching ratios in B- --> D0_(CP) K- decays with detailed CP eigenstate analysis.

Findings

Measured CP asymmetries A_CP+ = 0.35 +/- 0.13 (stat) +/- 0.04 (syst) and A_CP- = -0.06 +/- 0.13 (stat) +/- 0.04 (syst).

Determined ratios R_CP+ = 0.90 +/- 0.12 (stat) +/- 0.04 (syst) and R_CP- = 0.86 +/- 0.10 (stat) +/- 0.05 (syst).

Utilized 232 million B Bbar decays collected with the BABAR detector.

Abstract

We present a study of the decay B- --> D0_(CP) K- and its charge conjugate, where D0_(CP) is reconstructed in CP-even, CP-odd, and non-CP flavor eigenstates, based on a sample of 232 million Y(4S) --> B Bbar decays collected with the BABAR detector at the PEP-II e+e- storage ring. We measure the partial-rate charge asymmetries A_CP+, A_CP- and the ratios R_CP+, R_CP- of the B --> D0 K decay branching fractions as measured in CP+, CP-, and non-CP D0 decays: A_CP+ = 0.35 +/- 0.13 (stat) +/- 0.04 (syst) A_CP- = -0.06 +/- 0.13 (stat) +/- 0.04 (syst) R_CP+ = 0.90 +/- 0.12 (stat) +/- 0.04 (syst) R_CP- = 0.86 +/- 0.10 (stat) +/- 0.05 (syst)