First Observation of the $Σ_{c}^{*+}$ Baryon and a New Measurement of the $Σ_{c}^{+}$ Mass

Abstract

Using data recorded with the CLEO II and CLEO II.V detector configurations at the Cornell Electron Storage Rings, we report the first observation and mass measurement of the $Σ_c^{*+}$ charmed baryon, and an updated measurement of the mass of the $Σ_c^+$ baryon. We find $M(Σ_c^{*+})-M(Λ_c^+)$= 231.0 +- 1.1 +- 2.0 MeV, and $M(Σ_c^{+})-M(Λ_c^+)$= 166.4 +- 0.2 +- 0.3 MeV, where the errors are statistical and systematic respectively.