The shape of the $\Delta$ baryon in a covariant spectator quark model

Using a covariant spectator quark model that describes the recent lattice QCD data for the Delta electromagnetic form factors and all available experimental data on gamma N -> Delta transitions, we analyze the charge and magnetic dipole distributions of the Delta baryon and discuss its shape. We conclude that the quadrupole moment of the Delta is a good indicator of the deformation and that the Delta(+) charge distribution has an oblate shape. We also calculate transverse moments and find that they do not lead to unambiguous conclusions about the underlying shape.