First Observation of the Cabibbo-suppressed Decays Xi_c+ -> Sigma+ pi- pi+ and Xi_c+ -> Sigma- pi+ pi+ and Measurement of their Branching Ratios

Abstract

We report the first observation of two Cabibbo-suppressed decay modes, Xi_c+ -> Sigma+ pi- pi+ and Xi_c+ -> Sigma- pi+ pi+. We observe 59+/-14 over a background of 87, and 22+/-8 over a background of 13 events, respectively, for the signals. The data were accumulated using the SELEX spectrometer during the 1996-1997 fixed target run at Fermilab, chiefly from a 600GeV/c Sigma- beam. The branching ratios of the decays relative to the Cabibbo--favored Xi_c+ -> Xi- pi+ pi+ are measured to be B(Xi_c+ -> Sigma+ pi- pi+)/B(Xi_c+ -> Xi- pi+ pi+) = 0.48+/-0.20, and B(Xi_c+ -> Sigma- pi+ pi+)/B(Xi_c+ -> Xi- pi+ pi+) = 0.18+/-0.09, respectively. We also report branching ratios for the same decay modes of the Lambda_c+ relative to Lambda_c+ -> p K- pi+.

arXiv comment15 pages, 5 figures, version 2 as accepted in PLB

References in corpus (7)

• Big-Bang nucleosynthesis (Particle Data Group mini-review)
• The Cosmological Parameters 2006
• The SELEX Phototube RICH Detector
• Hadronic Production of Lambda_c from 600 GeV/c pion, sigma and proton beams
• Observation of the Cabibbo-suppressed decay Xi_c+ -> p K- pi+
• Measurements of ${\Xi }_c^{+}$ Branching Ratios
• Measurement of the relative branching ratio BR(Ξ_c^+ \to p^+ K^-π^+)\BR(Ξ_c^+ \to Ξ^- π^+ π^+)

Cited by in corpus (4)

• First measurements of absolute branching fractions of the ${\Xi }_c^{+}$ baryon at Belle
• Determination of the pi Sigma scattering lengths from the weak decays of Lambda_c
• Fragmentation-fraction ratio $f_{{\Xi }_b}/f_{{\Lambda }_b}$ in $b$- and $c$-baryon decays
• Nonleptonic three-body charmed baryon weak decays with H(15)