Measurements of the Branching Fractions ${\cal B}(B^{-} \to \bar{\Lambda}_{c}^{-} \Xi_{c}^{'0})$, ${\cal B}(B^{-} \to \bar{\Lambda}_{c}^{-} \Xi_{c}(2645)^{0})$ and ${\cal B}(B^{-} \to \bar{\Lambda}_{c}^{-} \Xi_{c}(2790)^{0}) $

TL;DR

This paper reports the first measurements of specific B meson decay branching fractions involving charmed baryons, using a large data sample from the Belle experiment, including the first observation of one decay mode.

Contribution

First measurement of branching fractions for B- decays to anti-Lambda_c- and various Xi_c states, providing new experimental data on these rare decay processes.

Findings

Branching fraction for B- to anti-Lambda_c- and Xi_c(2790)0 measured as (1.1 ± 0.4 ± 0.2)×10^{-3}

Upper limits set for B- to anti-Lambda_c- and Xi_c'0 or Xi_c(2645)0 decays

First measurements of these decay modes using 711 fb^{-1} data from Belle

Abstract

Using the data sample of 711 fb$^{-1}$ of $\Upsilon(4S)$ on-resonance data taken by the Belle detector at the KEKB asymmetric-energy electron-positron collider, we present the first measurements of branching fractions of the decays $B^{-} \to \bar{\Lambda}_{c}^{-} \Xi_{c}^{'0}$, $B^{-} \to \bar{\Lambda}_{c}^{-} \Xi_{c}(2645)^{0}$, and $B^{-} \to \bar{\Lambda}_{c}^{-} \Xi_{c}(2790)^{0} $. The signal yields for these decays are extracted from the recoil mass spectrum of the system recoiling against $\bar{\Lambda}_{c}^{-}$ baryons in selected $B^-$ candidates. The branching fraction of $B^{-} \to \bar{\Lambda}_{c}^{-} \Xi_{c}(2790)^{0}$ is measured to be $ (1.1 \pm 0.4 \pm 0.2)\times 10^{-3}$, where the first uncertainty is statistical and the second systematic. The 90\% credibility level upper limits on ${\cal B}(B^{-} \to \bar{\Lambda}_{c}^{-} \Xi_{c}^{'0})$ and ${\cal B}(B^{-} \to \bar{\Lambda}_{c}^{-} \Xi_{c}(2645)^{0})$ are determined to be $6.5\times 10^{-4}$ and $7.9\times 10^{-4}$, respectively.