FIRST OBSERVATION OF THE Σ_c~(*+) CHARMED BARYON, AND NEW MEASUREMENTS OF THE Σ_C~0, Σ_C~+, Σ_c~(++), AND Ω_c~0 CHARMED BARYONS

摘要

Using ～13.7 fb~(-1) of e~+ e~- collision data recorded at near the γ(4S) resonance by the CLEO Ⅱ and CLEO Ⅱ.Ⅴ detector configurations on the Cornell Electron Storage Ring, we present the world's most precise measurements of the Σ_c~0, Σ_c~+, and Σ_c~(++) charmed-baryon masses as well as the first measurements of the intrinsic widths of the Σ_c~0 and Σ_c~(++) baryons. We also report on the first observation and mass measurement of the Σ_c~(*+) charmed baryon, M(Σ_c~(*+)) -M(Λ_c~+) = (231.0 +- l.l[stat] +- 2.0[syst]) MeV/c~2, and the first CLEO observation of the Ω_c~0 baryon, for which we measure a mass M(Ω_c~0) = (2694.6 +- 2.6[stat] +- 2.4[syst]) MeV/c~2 from a sample of (40.4 +- 9.0[stat]) candidate events. All new results are preliminary.