Weak Quasielastic Production of Hyperons

TL;DR

This paper investigates antineutrino-induced quasielastic hyperon production on nucleons and nuclei, incorporating nuclear medium effects and hyperon polarization, to improve understanding of weak interactions involving strangeness.

Contribution

It provides a comprehensive analysis of hyperon production including nuclear effects and hyperon polarization, using form factors derived from neutrino scattering and decays, which is novel in this context.

Findings

Hyperon production cross sections calculated with nuclear medium effects.

Hyperon polarization components analyzed for future experimental insights.

Contribution of hyperon decay to weak pion production quantified.

Abstract

We present the results for antineutrino induced quasielastic hyperon production from nucleon and nuclear targets \cite{Alam:2014bya,Singh:2006xp}. The inputs are the nucleon-hyperon(N--Y) transition form factors determined from the analysis of neutrino-nucleon scattering and semileptonic decays of neutron and hyperons using SU(3) symmetry. The calculations for the nuclear targets are done in local density approximation. The nuclear medium effects(NME) like Fermi motion, Pauli blocking and final state interaction(FSI) effects due to hyperon-nucleon scattering have been taken into account. The hyperons giving rise to pions through weak decays also contribute to the weak pion production in addition to the $\Delta$ excitation mechanism which dominates in the energy region of $<$ 0.7 GeV. We also present the results of longitudinal and perpendicular components of polarization of final hyperon \cite{Akbar:2016awk}. These measurements in the future accelerator experiments with antineutrinos may give some information on axial vector and pseudoscalar form factors in the strangeness sector.