The Production of Λ and Σ0 Hyperons in Antineutrino-Proton Collisions

We obtain total and differential cross sections for the strangeness changing charged current reactions, ν(bar sign)L + p → Λ + L+ and ν(bar sign)L + p → Σ0 + L+ where L stands for an electron, muon, or tau lepton. We calculate these cross sections from near threshold to several GeV. We also obtain the the contributions of the various form factors to the total and differential cross sections. We do this in support of possible experiments which have been proposed by the MINERνA Collaboration. The calculation is phenomenologically based and makes use of SU(3) relations to obtain the standard vector form factors. The axial current form factor for the Λ reaction is obtained via Λ beta decay data but for the Σ0 process is obtained via SU(2) relations from Σ- beta decay data since Σ0 does not undergo beta decay. We also make use of theoretical estimates for the contribution of the pseudoscalar form factor and for the FE and FS form factors to the processes described here. We note that the latter two form factors are second class form factors and are forbidden by G-parity for the p ↔ n transition but are not forbidden here. We discuss our results and show that for the Λ case most of the contributions come from the vector and axial vector form factors and that for the Σ0 case, only the vector current form factor makes a substantial contribution. Thus the latter reaction might be a suitable test of the SU(3) obtained form factors which has become an interesting question