BaBar: sin(2beta+gamma)

TL;DR

This paper reports measurements of time-dependent CP asymmetries in B0 decays to D(*)pi/rho, combining results to interpret the unitarity triangle angles, providing bounds on |sin(2beta+gamma)| and |2beta+gamma|.

Contribution

First measurement of CP asymmetries in these B0 decay modes and their combination to constrain the unitarity triangle angles.

Findings

|sin(2beta+gamma)| > 0.64 at 68% CL

|2beta+gamma| = (90 ± 43)° from Bayesian analysis

Results contribute to understanding CP violation in the Standard Model

Abstract

The time-dependent CP asymmetries in fully reconstructed B0 --> D(*)pi/rho decays (new preliminary result), and in partially reconstructed B0 --> D(*)pi decays, are measured with the BaBar detector at the PEP-II asymmetric B factory at SLAC, using 232 million Y(4S) -> BB decays. We combine the above results and, using other measurements and theoretical assumptions, we interpret them in terms of the angles of the unitarity triangle describing the Cabibbo-Kobayashi-Maskawa matrix. We find |sin(2beta+gamma)|>0.64(0.42) at 68%(90%) confidence level using a frequentistic approach and |2beta+gamma|=(90 +- 43)o using a Bayesian approach.