Charge Distributions of Moving Nucleons

We introduce relativistic charge distributions for targets with arbitrary average momentum, providing a natural interpolation between the usual Breit frame and infinite-momentum frame distributions. Among the remarkable results, we find that Breit frame distributions can be interpreted from a phase-space perspective as internal charge quasidensities in the rest frame of a localized target, without any relativistic correction. Moreover, we show that the unexpected negative center observed in the unpolarized neutron infinite-momentum frame charge distribution results from a magnetization contribution generated by the Wigner rotation.