Observation of ηc decay into Σ+(Σ)over-bar- and (sic)-((sic))over bar + final states

Abstract

Using a data sample of 2.25 x 10(8) J/psi events collected with the BESIII detector, we present the first observation of the decays of eta(c) mesons to Sigma(+)(Sigma) over bar (-) and (sic)(-)<((sic))over bar>(+) .The branching fractions are measured to be (2.11 +/- 0.28(stat) +/- 0.18(syst) +/- 0.50(PDG)) x 10(-3) and (0.89 +/- 0.16(stat) +/- 0.08(syst) +/- 0.21(PDG)) x 10(-3) for eta(c) -> Sigma(+)(Sigma) over bar (-) and (sic)(-)<((sic))over bar>(+) , respectively. These branching fractions provide important information on the helicity selection rule in charmonium- decay processes. DOI: 10.1103/PhysRevD.87.012003