Dalitz plot analysis of B−→D+π−π−

Abstract

We report on a Dalitz plot analysis of B − → D + π − π − decays, based on a sample of about 383 × 10 6 Υ ( 4 S ) → B ¯¯¯ B decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We find the total branching fraction of the three-body decay: B ( B − → D + π − π − ) = ( 1.08 ± 0.03 ± 0.05 ) × 10 − 3 . We observe the established D * 0 2 and confirm the existence of D * 0 0 in their decays to D + π − , where the D * 0 2 and D * 0 0 are the 2 + and 0 + c ¯ u P -wave states, respectively. We measure the masses and widths of D * 0 2 and D * 0 0 to be: m D * 0 2 = ( 2460.4 ± 1.2 ± 1.2 ± 1.9 ) MeV / c 2 , Γ D * 0 2 = ( 41.8 ± 2.5 ± 2.1 ± 2.0 ) MeV , m D * 0 0 = ( 2297 ± 8 ± 5 ± 19 ) MeV / c 2 , and Γ D * 0 0 = ( 273 ± 12 ± 17 ± 45 ) MeV . The stated errors reflect the statistical and systematic uncertainties, and the uncertainty related to the assumed composition of signal events and the theoretical model.