A covariant model for the ${\gamma }^{\ast }N\to N^{\ast }(1520)$ reaction

Abstract

We apply the covariant spectator quark model to the study of the electromagnetic structure of the $N^{\ast }(1520)$ state ($J^P={\frac{3}{2}}^{-}$), an important resonance from the second resonance region in both spacelike and timelike regimes. The contributions from the valence quark effects are calculated for the ${\gamma }^{\ast }N\to N^{\ast }(1520)$ helicity amplitudes. The results are used to parametrize the meson cloud dominant at low $Q^2$.

Comments: 3 figure, 3 pages. Contribution to the 13th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon (MENU 2013), Rome, September-October 2013