Using the Single Quark Transition Model to predict nucleon resonance amplitudes

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 ${\gamma }^{\ast }N\to N^{\ast }(1650)$, ${\gamma }^{\ast }N\to N^{\ast }(1700)$, ${\gamma }^{\ast }N\to \mathrm{\Delta }(1620)$, and ${\gamma }^{\ast }N\to \mathrm{\Delta }(1700)$. The analysis is restricted to reactions with proton targets. The predictions for the transition amplitudes are valid for $Q^2>2$ GeV${}^2$.