Cabibbo suppressed hyperon production off nuclei induced by antineutrinos

Abstract

In this work, we study the production of Σ and Λ hyperons in strangeness-changing ΔS = −1 charged-current interactions of muon antineutrinos on nuclear targets. At the nucleon level, besides quasielastic scattering, we consider the inelastic mechanism in which a pion is produced alongside the hyperon. Its relevance for antineutrinos with energies below 2 GeV is conveyed in integrated and differential cross sections. We observe that the distributions on the angle between the hyperon and the final lepton are clearly different for quasielastic and inelastic processes. Hyperon final-state interactions, modeled with an intranuclear cascade, lead to a significant transfer from primary produced Σ’s into final Λ’s. They also cause considerable energy loss, which is apparent in hyperon energy distributions. We have investigated Λ production off 40Ar in the conditions of the recently reported MicroBooNE measurement. We find that the Λπ contribution, dominated by Σ*(1385) excitation, accounts for about one third of the cross section.