Inclusive production of the charmed baryon Λc+ from e+e− annihilations at s=10.55 GeV

Abstract

We report results on inclusive production of the charmed baryon ${{\Lambda }_c}^{+}$ from $e^{+}{e}^{-}$ annihilations at $\sqrt{s}=10.5\mathrm{}$ GeV. Measurements are presented of the inclusive cross section times branching fraction for the continuum production of ${{\Lambda }_c}^{+}$ as observed in six different decay modes, and of a new, improved value of the ${{\Lambda }_c}^{+}$ mass. The inclusive cross section times the branching fraction into $p{K}^{-}{\pi }^{+}$ is measured to be 10.0±1.5±1.5 pb summed over all $x_p$. The branching fractions of ${{\Lambda }_c}^{+}$ into $p{\overline{K}}^0$, $p{\overline{K}}^0{\pi }^{+}{\pi }^{-}$, $\Lambda {\pi }^{+}$, $\Lambda {\pi }^{+}{\pi }^{-}{\pi }^{+}$, and ${\Xi }^{-}{K}^{+}{\pi }^{+}$ relative to that into $p{K}^{-}{\pi }^{+}$ are measured to be 0.44±0.07±0.05, 0.43±0.12±0.04, 0.18±0.03±0.03, 0.65±0.11±0.12, and 0.15±0.04±0.03, respectively. The ${{\Lambda }_c}^{+}$ mass is measured to be 2284.7±0.6±0.7 MeV/${\mathit{c}}^2$. The measured momentum distributions for continuum production of ${{\Lambda }_c}^{+}$ are compared to analytical fragmentation functions and to other measurements.