Using data collected by the CLEO III detector at CESR, we report on the first observation of the decays Λ c +→Λ π + π + π - π 0 and Λ c +→Λ ωπ +. The branching fractions are measured relative to the pK - π + mode; we find B(Λ c +→Λ π + π + π - π 0)/B(Lambda; c +→pK - π +) = 0.36±0.09(stat) ±0.09(syst) and B(Λ c +→Λ ωπ +)/B(Λ c +→pK - π +) = 0.24±0.06(stat)±0.06(syst). We also observe a small excess of events in Λ c +→Λ ηπ +, η→π + π - π 0 from which we find B(Λ c +→Λ ηπ +)/B(Λ c +→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 Λ c +→Λ ηπ +, η-γ γ. We find that the combined branching fractions for Λ c +→Lambda; ωπ + and Λ c +→Λπ + π + π - π 0)B(Λ c + comprise (87±13) of the total Λ rate. We set an upper limit on B(Λ c +→Λπ + π + π - 0)/BΛ c +→pK - π + for non-ω and non-η modes of 0.13 at 90% confidence level.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)