First Observation of the Decay $B^{0}\to D^{*+}D^{*-}$

TL;DR

This paper reports the first observation of the decay B0 -> D*+D*-, with four candidates detected and a measured branching ratio indicating its significance for CP asymmetry studies.

Contribution

First observation of the B0 -> D*+D*- decay mode with measured branching ratio and background estimation, expanding understanding of B meson decays.

Findings

Observed four B0 -> D*+D*- candidates

Measured decay rate Br(B0 -> D*+D*-) = (6.2 +4.0-2.9 ± 1.0) x 10^{-4}

Background probability for observed candidates is 1.1 x 10^{-4}

Abstract

We have observed four fully reconstructed B0 -> D*+D*- candidates in 5.8 million Upsilon(4S) -> BBbar decays recorded with the CLEO detector. The background is estimated to be 0.31 +- 0.10 events. The probability that the background could produce four or more signal candidates with the observed distribution among D*+ and D*- decay modes is 1.1 X 10^{-4}. The measured decay rate, Br(B0 -> D*+D*-) = [6.2 +4.0-2.9 (stat) +- 1.0(syst)] X 10^{-4}, is large enough for this decay mode to be of interest for the measurement of a time-dependent CP asymmetry.