Using the Single Quark Transition Model to predict nucleon resonance amplitudes

TL;DR

This paper combines the single quark transition model with the covariant spectator quark model to predict nucleon resonance amplitudes for various transitions at high momentum transfer, aiding understanding of nucleon structure.

Contribution

It introduces a novel approach by integrating two quark models to estimate helicity amplitudes for multiple nucleon resonance transitions at high Q^2.

Findings

Predicted transition amplitudes for several nucleon resonances.

Validated predictions for Q^2 > 2 GeV^2.

Provided functional forms for amplitude calculations.

Abstract

We present predictions for the $\gamma^\ast N \to N^\ast$ helicity amplitudes, where $N^\ast$ is a member of the $[70,1^-]$ supermultiplet. We combine the results from the single quark transition model for the helicity amplitudes with the results of the covariant spectator quark model for the $\gamma^\ast N \to N^\ast(1535)$ and $\gamma^\ast N \to N^\ast(1520)$ transitions. The theoretical estimations from the covariant spectator quark model are used to calculate three independent functions $A,B$, and $C$ of $Q^2$, where $Q^2=-q^2$ and $q$ is the momentum transfer. With the knowledge of the functions $A,B$, and $C$ we estimate the helicity amplitudes for the transitions $\gamma^\ast N \to N^\ast(1650)$, $\gamma^\ast N \to N^\ast(1700)$, $\gamma^\ast N \to \Delta(1620)$, and $\gamma^\ast N \to \Delta(1700)$. The analysis is restricted to reactions with proton targets. The predictions for the transition amplitudes are valid for $Q^2 > 2$ GeV$^2$.