Weak Quasielastic Production of Hyperons and Threshold Production of Two Pions

TL;DR

This paper investigates weak quasielastic hyperon production and two-pion production near threshold induced by neutrinos, incorporating nuclear medium effects, hyperon-nucleon form factors, and resonance contributions, with results compared to experimental data.

Contribution

It provides a comprehensive analysis of hyperon and two-pion production processes induced by neutrinos, including nuclear effects and resonance contributions, which enhances understanding of these interactions.

Findings

Cross sections calculated and compared with experimental data.

Nuclear medium effects significantly influence hyperon production.

Resonance contributions affect two-pion production near threshold.

Abstract

We have studied quasielastic charged current hyperon production induced by $\bar\nu_\mu$ on free nucleon and the nucleons bound inside the nucleus and the results are presented for several nuclear targets like $^{40}Ar$, $^{56}Fe$ and $^{208}Pb$. The hyperon-nucleon transition form factors are determined from neutrino-nucleon scattering and semileptonic decays of neutron and hyperons using SU(3) symmetry. The nuclear medium effects(NME) due to Fermi motion and final state interaction(FSI) effect due to hyperon-nucleon scattering have been taken into account. Also we have studied two pion production at threshold induced by neutrinos off nucleon targets. The contribution of nucleon, pion, and contact terms are calculated using Lagrangian given by nonlinear $\sigma$ model. The contribution of the Roper resonance has also been taken into account. The numerical results for the cross sections are presented and compared with the experimental results from ANL and BNL.