Study of the Decays B0 --> D(*)+D(*)-

TL;DR

This study measures branching ratios and performs angular analysis of B0 decays to D(*)+D(*)- final states, providing insights into CP violation potential in neutral B meson decays.

Contribution

It reports the first angular analysis of B0 --> D*+D*- decay and sets limits on other decay modes, advancing understanding of B meson decay dynamics.

Findings

Br(B0 --> D*+D*-) = (9.9+4.2-3.3+-1.2)e-4

Limits: Br(B0 --> D*+D-) < 6.3e-4, Br(B0 --> D+D-) < 9.4e-4

CP-even fraction > 0.11 at 90% CL

Abstract

The decays B0 --> D*+D*-, B0 --> D*+D- and B0 --> D+D- are studied in 9.7 million Y(4S) --> BBbar decays accumulated with the CLEO detector. We determine Br(B0 --> D*+D*-) = (9.9+4.2-3.3+-1.2)e-4 and limit Br(B0 --> D*+D-) < 6.3e-4 and Br(B0 --> D+D-) < 9.4e-4 at 90% confidence level (CL). We also perform the first angular analysis of the B0 --> D*+D*- decay and determine that the CP-even fraction of the final state is greater than 0.11 at 90% CL. Future measurements of the time dependence of these decays may be useful for the investigation of CP violation in neutral B meson decays.