Probing Hadronic Structure with The Decay $Δ\rightarrow Nl^+l^-$

Abstract

We compute the branching ratio for $Δ\rightarrow Ne^+e^-$ and $Δ\rightarrow Nμ^+μ^-$ in chiral perturbation theory and find that both decays should be observable at CEBAF. With sufficiently low thresholds on the $e^+e^-$ invariant mass a branching ratio of $\sim 10^{-5}$ may be observed for $Δ\rightarrow Ne^+e^-$. For the $Δ\rightarrow Nμ^+μ^-$ decay mode we predict a branching ratio of $3\times 10^{-7}$. The dependence of the M1 and E2 amplitudes on the momentum transfer will provide a useful test of chiral perturbation theory which predicts $\sim 20\%$ variation over the allowed kinematic range.