Measurements of the Branching fractions for $B_(s) -> D_(s)\pi\pi\pi$ and $\Lambda_b^0 -> \Lambda_c^+\pi\pi\pi$

TL;DR

This paper reports precise measurements of branching fractions for specific B and Lambda_b decays involving three-pion final states, using LHCb data at 7 TeV, providing improved accuracy over previous results.

Contribution

First measurements of these branching fractions relative to simpler decays, with enhanced precision and additional partial decay rate data for excited charm hadrons.

Findings

Branching ratio for B^0-bar to D^+π^-π^+π^- is 2.38±0.11±0.21

Branching ratio for B^- to D^0π^-π^+π^- is 1.27±0.06±0.11

Branching ratio for B_s^0-bar to D_s^+π^-π^+π^- is 2.01±0.37±0.20

Abstract

Branching fractions of the decays $H_b\to H_c\pi^-\pi^+\pi^-$ relative to $H_b\to H_c\pi^-$ are presented, where $H_b$ ($H_c$) represents B^0-bar($D^+$), $B^-$ ($D^0$), B_s^0-bar ($D_s^+$) and $\Lambda_b^0$ ($\Lambda_c^+$). The measurements are performed with the LHCb detector using 35${\rm pb^{-1}}$ of data collected at $\sqrt{s}=7$ TeV. The ratios of branching fractions are measured to be B(B^0-bar -> D^+\pi^-\pi^+\pi^-)/ B(B^0-bar -> D^+\pi^-) = 2.38\pm0.11\pm0.21 B(B^- -> D^0\pi^-\pi^+\pi^-) / B(B^- -> D^0\pi^-) = 1.27\pm0.06\pm0.11 B(B_s^0-bar -> D_s^+\pi^-\pi^+\pi^-) / B(B_s^0-bar -> D_s^+\pi^-) = 2.01\pm0.37\pm0.20 B(\Lambda_b^0->\Lambda_c^+\pi^-\pi^+\pi^-) / B(\Lambda_b^0 -> \Lambda_c^+\pi^-) = 1.43\pm0.16\pm0.13. We also report measurements of partial decay rates of these decays to excited charm hadrons. These results are of comparable or higher precision than existing measurements.