Measurement of the relative branching ratio BR(Ξ_c^+ \to p^+ K^-π^+)\BR(Ξ_c^+ \to Ξ^- π^+ π^+)

Abstract

We report the observation of the Cabibbo suppressed decay Ξ_c^+ \to p K^-π^+ using data collected with the FOCUS spectrometer during the 1996--97 Fermilab fixed target run. We find a Ξ_c^+ signal peak of 202\pm35 events. We have measured the relative branching ratios BR(Ξ^+_c\to p K^-π^+)/BR(Ξ^+_c\toΞ^-π^+π^+)= 0.234 \pm 0.047 \pm 0.022 and BR(Ξ^+_c\to p \bar{K}^*(892)^0)/BR(Ξ^+_c\to p K^-π^+)= 0.54 \pm 0.09 \pm 0.05 .