Using data collected by the CLEO III detector at CESR, we report on the first observation of the decays Λc+→Λ π+ π+ π- π0 and Λc+→Λ ωπ+. The branching fractions are measured relative to the pK- π+ mode; we find B(Λc+→Λ π+ π+ π- π0)/B(Lambda;c +→pK- π+) = 0.36±0.09(stat) ±0.09(syst) and B(Λc+→Λ ωπ+)/B(Λc+→pK- π+) = 0.24±0.06(stat)±0.06(syst). We also observe a small excess of events in Λc+→Λ ηπ+, η→π+ π- π0 from which we find B(Λc +→Λ ηπ+)/B(Λc +→pK- π+) = 0.41±0.17±0. 10 with a corresponding limit of <0.65% at 90% confidence level. This rate is consistent with previous measurements of Λc +→Λ ηπ+, η-γ γ. We find that the combined branching fractions for Λc +→Lambda; ωπ+ and Λc +→Λπ+ π+ π- π0)B(Λc+ comprise (87±13) of the total Λ rate. We set an upper limit on B(Λc +→Λπ+ π+ π- 0)/BΛc+→pK- π+ for non-ω and non-η modes of 0.13 at 90% confidence level.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics