Isoscalar-Isovector Interferences in $\pi N\to N{e}^{+}{e}^{-}$ Reactions as a Probe of Baryon Resonance Dynamics

Abstract

The isoscalar-isovector ($\rho -\omega$) interferences in the exclusive reactions ${\pi }^{-}p\to n{e}^{+}{e}^{-}$ and ${\pi }^{+}n\to p{e}^{+}{e}^{-}$ near the $\omega$ threshold leads to a distinct difference of the dielectron invariant mass distributions depending on beam energy. The strength of this effect is determined by the coupling of resonances to the nucleon vector-meson channels and other resonance properties. Therefore, a combined analysis of these reactions can be used as a tool for determining the baryon resonance dynamics.