Determination of the ?c+ spin via the reaction e+e- ? ?c(?)over-barc

Abstract

We report on a comparison of two possible Lambda(+)(c) spin hypotheses, J = 1/2 and 3/2, via the process e(+)e(-) -> Lambda(c)(Lambda) over bar (c) using the angular distributions of Lambda(+)(c) decays into pK(S)(0), Lambda pi(+), Sigma(0)pi(+) and Sigma(+)pi(0). The data were recorded at root sp = 4.6 GeV with the BESIII detector and correspond to an integrated luminosity of 587 pb(-1). The. thornc spin is determined to be J = 1/2, with this value favored over the 3 2 hypothesis with a significance corresponding to more than 6 Gaussian standard deviations.