First measurements of hyperon time-like form factors at large Q2 and evidence of diquark correlations

Abstract

Using e+e− annihilation data taken with the CLEO-c detector at s = 3770 MeV and 4170 MeV, we report the first measurements of the electromagnetic form factors of the Λ0, Σ0, Σ+, Ξ0, Ξ−, and Ω− hyperons for the large timelike momentum transfers of |Q2| = 14.2 GeV2 and 17.4 GeV2, respectively. The enhancement in Λ0 production over that of Σ0, both of which have the same uds quark content, gives evidence for significant diquark correlations in these hyperons. Improved measurements of the branching fractions of ψ(2S) to hyperon–antihyperon pairs are also reported.