A precise isospin analysis of B -> Dbar(*) D(*) K decays

TL;DR

This paper performs a detailed isospin analysis of B -> Dbar(*) D(*) K decays using recent experimental data, providing insights into decay amplitudes, phases, and implications for CKM matrix measurements.

Contribution

It introduces a precise isospin analysis framework for these decays and presents new measurements of branching fraction ratios and their impact on unitarity parameter determinations.

Findings

Determined isospin amplitudes and phases for B decays.

Measured the ratio of B+ to B0 production at Upsilon(4S).

Discussed implications for sin(2 beta) and cos(2 beta) measurements.

Abstract

We present a precise isospin analysis of the B -> Dbar(*) D(*) K decays using new recent experimental measurements on these final states. The decays B -> Dbar(*) D(*) K, originating from b -> c cbar s transitions, are linked by a rich set of isospin properties. The isospin relations that connect the decay modes are presented and a fit is performed to obtain the isospin amplitudes and phases. We discuss the results of the fit and present a new measurement of the ratio of branching fractions BR(Upsilon(4S) -> B+ B-) and BR(Upsilon(4S) -> B0 B0bar). We finally discuss the implications of our findings for the measurement of the unitarity matrix parameters sin(2 beta) and cos(2 beta) using these decays.