N~* (1535) electroproduction at high Q~2

摘要

A covariant spectator quark model is applied to study the γN → N~*(1535) reaction in the large Q~2 region. Starting from the relation between the nucleon and N~*(1535) systems, the N~*(1535) valence quark wave function is determined without the addition of any parameters. The model is then used to calculate the γN → N~*(1535) transition form factors. A very interesting, useful relation between the A_(1/2) and S_(1/2) helicity amplitudes for Q~2 > 2 GeV~2, is also derived.