Helicity Amplitude Analysis of e⁺e^-→ψ(2S) →γχ_cJ→γΛ^-Λ→γ pπ^--pπ⁺

An analysis of the helicity amplitude is performed on the process e⁺e^-→ψ(2S) →γχ_cJ→γΛ^-Λ→γ pπ^--pπ⁺. The joint angular distributions for each decay chain are given, and we focus on discussing the E1 contributions to ψ(2S) radiative decays, and the violation of the helicity selection rule in χ_cJ decays into hyperon pairs, together with the possibility of observing parity violation in successive hyperon decays.