Observation of $B^0 \to D^{*-} (5π)^+$, $B^+ \to D^{*-} (4π)^{++}$ and $B^+ \to \bar{D}^{*0} (5π)^+$

Abstract

We report the first observation of a number of decay modes of the B meson, namely $B^0 \to D^{*-} (5π)^+$, $B^+ \to D^{*-} (4π)^{++}$ and $B^+ \to \bar{D}^{*0} (5π)^+$, where $(nπ)$ implies the combination of n charged pions. The analysis is based on a 140 fb$^{-1}$ data sample collected at the $Υ(4S)$ resonance with the Belle detector at KEKB. We measure ${\cal{B}}(B^0 \to D^{*-} (5π)^+) = (4.72 \pm 0.59 \pm 0.71) \times 10^{-3}$, ${\cal{B}}(B^+ \to D^{*-} (4π)^{++} = (2.56 \pm 0.26 \pm 0.33) \times 10^{-3}$ and ${\cal{B}}(B^+ \to \bar{D}^{*0} (5π)^+) = (5.67 \pm 0.91 \pm 0.85) \times 10^{-3}$. We also provide improved measurements of the branching fractions for the decay modes $B^0 \to D^{*-} (3π)^+$, $B^+ \to \bar{D}^{*0} (3π)^+$ and $B^0 \to \bar{D}^{*0} (4π)^0$.