Measurement of time-dependent CP asymmetries in B0->D(*)+-pi-+ and B0->D+-rho-+ decays

TL;DR

This paper reports updated measurements of time-dependent CP asymmetries in B0 decays to D(*)+-pi-+ and D+-rho-+, providing constraints on the CKM unitarity triangle angles with data from the BaBar detector.

Contribution

The study presents the first comprehensive analysis of CP asymmetries in these decay modes using a large dataset, refining previous measurements and interpretations.

Findings

Measured CP asymmetry parameters with improved precision.

Established lower bounds on |sin(2beta+gamma)| at 68% and 90% confidence levels.

Constrained the CKM unitarity triangle angles based on the results.

Abstract

We present updated results on time-dependent CP asymmetries in fully reconstructed B0->D(*)+-pi-+ and B0->D+-rho-+ decays in approximately 232 million Y(4S)->BBbar events collected with the BaBar detector at the PEP-II asymmetric-energy B factory at SLAC. From a time-dependent maximum likelihood fit we obtain for the parameters related to the CP violation angle 2beta+gamma: a^{D\pi} = -0.010 +/- 0.023 +/- 0.007, c_{\rm lep}^{D\pi} = -0.033 +/- 0.042 +/- 0.012, a^{D^*\pi} = -0.040 +/- 0.023 +/- 0.010, c_{\rm lep}^{D^*\pi} = 0.049 +/- 0.042 +/- 0.015, a^{D\rho} = -0.024 +/- 0.031 +/- 0.009, c_{\rm lep}^{D\rho} = -0.098 +/- 0.055 +/- 0.018, where the first error is statistical and the second is systematic. Using other measurements and theoretical assumptions, we interpret the results in terms of the angles of the Cabibbo-Kobayashi-Maskawa unitarity triangle and find |sin(2beta+gamma)| > 0.64 (0.40) at 68% (90%) confidence level.