Measurement of the branching fraction of Λ+c→pω decay at Belle.

Abstract

Using 980.6 fb−1 of data collected with the Belle detector operating at the KEKB asymmetric-energy eþe− collider, we present a measurement of the branching fraction of the singly Cabibbo-suppressed decay Λþ c → pω. A clear Λþ c signal is observed for Λþ c → pω with a statistical significance of 9.1 standard deviations, and we measure the ratio of branching fractions BðΛþ c → pωÞ=BðΛþ c → pK−πþÞ ¼ ð1.32 0.12ðstatÞ 0.10ðsystÞÞ × 10−2, from which we infer the branching fraction BðΛþ c → pωÞ ¼ ð8.27 0.75ðstatÞ 0.62ðsystÞ 0.42ðrefÞÞ × 10−4. The first quoted uncertainty is statistical, the second systematic, and the third from the reference mode Λþ c → pK−πþ.