Measurement of the absolute branching fractions B → Dπ, D*π, D**π with a missing mass method

Abstract

We present branching fraction measurements of charged and neutral B decays to D π − , D ∗ π − , and " D ** " π − with a missing mass method, based on a sample of 231 × 10 6 Υ ( 4 S ) → B ¯¯¯ B pairs collected by the BABAR detector at the PEP-II e + e − collider. One of the B mesons is fully reconstructed and the other one decays to a reconstructed charged π and a companion charmed meson identified by its recoil mass, inferred by kinematics. Here " D ** " refers to the sum of all the nonstrange charm meson states with masses in the range 2.2 - 2.8 GeV / c 2 . We measure the branching fractions: B ( B − → D 0 π − ) = ( 4.49 ± 0.21 ± 0.23 ) × 10 − 3 , B ( B − → D * 0 π − ) = ( 5.13 ± 0.22 ± 0.28 ) × 10 − 3 , B ( B − → " D ** 0 " π − ) = ( 5.50 ± 0.52 ± 1.04 ) × 10 − 3 , B ( ¯¯¯ B 0 → D + π − ) = ( 3.03 ± 0.23 ± 0.23 ) × 10 − 3 , B ( ¯¯¯ B 0 → D * + π − ) = ( 2.99 ± 0.23 ± 0.24 ) × 10 − 3 , B ( ¯¯¯ B 0 → " D ** + " π − ) = ( 2.34 ± 0.65 ± 0.88 ) × 10 − 3 , and their ratios.