A New Measurement of $B\to D^{*}\pi$ Branching Fractions

TL;DR

This paper presents new measurements of the branching fractions for B meson decays to D* pi using data from the CLEO-II detector, improving the precision of these fundamental parameters.

Contribution

The study provides the first precise measurements of B -> D* pi branching fractions without D reconstruction, utilizing a novel kinematic reconstruction method.

Findings

Measured BR(B0 -> D*+ pi-) = (2.81 +/- 0.11 +/- 0.21 +/- 0.05) x 10^{-3}

Measured BR(B- -> D*0 pi-) = (4.34 +/- 0.33 +/- 0.34 +/- 0.18) x 10^{-3}

Demonstrates effective reconstruction technique with low background.

Abstract

The decays Upsilon(4S) -> BB, followed by B -> D* pi and D* -> D pi, permit reconstruction of all kinematic quantities that describe the sequence without reconstruction of the D, with reasonably low backgrounds. Using an integrated e+e- luminosity of 3.1 fb^{-1} accumulated at the Upsilon(4S) by the CLEO-II detector, we report measurements of BR(B0 -> D*+ pi-) = (2.81 +/- 0.11 +/- 0.21 +/- 0.05) x 10^{-3} and BR(B- -> D*0 pi-) = (4.34 +/- 0.33 +/- 0.34 +/- 0.18) x 10^{-3}.