Measurement of the branching fraction ${\mathcal{B}}(\Lambda^0_b\rightarrow \Lambda^+_c\pi^-\pi^+\pi^-)$ at CDF

Abstract

We report an analysis of the $\Lambda^0_b\rightarrow\Lambda^+_c\pi^-\pi^+\pi^-$ decay in a data sample collected by the CDF II detector at the Fermilab Tevatron corresponding to 2.4 fb$^{-1}$ of integrated luminosity. We reconstruct the currently largest samples of the decay modes $\Lambda^0_b\rightarrow \Lambda_c(2595)^+\pi^-$ (with $\Lambda_c(2595)^+\rightarrow\Lambda^+_c\pi^+\pi^-$), $\Lambda^0_b\rightarrow \Lambda_c(2625)^+\pi^-$ (with $\Lambda_c(2625)^+\rightarrow\Lambda^+_c\pi^+\pi^-$), $\Lambda^0_b\rightarrow \Sigma_c(2455)^{++}\pi^-\pi^-$ (with $\Sigma_c(2455)^{++}\rightarrow\Lambda^+_c\pi^+$), and $\Lambda^0_b\rightarrow \Sigma_c(2455)^0\pi^+\pi^-$ (with $\Sigma_c(2455)^0\rightarrow\Lambda^+_c \pi^-$) and measure the branching fractions relative to the $\Lambda^0_b\rightarrow\Lambda^+_c\pi^-$ branching fraction. We measure the ratio $\BR(\Lambda^0_b\rightarrow \Lambda^+_c\pi^-\pi^+\pi^-) /\BR(\Lambda^0_b\rightarrow \Lambda^+_c \pi^-) = 3.04 \pm 0.33(\text{stat})^{+0.70}_{-0.55}(\text{syst})$ which is used to derive $\BR(\Lambda^0_b\rightarrow \Lambda^+_c\pi^-\pi^+\pi^-)= (26.8^{+11.9}_{-11.2})\times10^{-3}$.