Constraining proton geometric fluctuations with incoherent diffractive vector meson production

Abstract

We calculate coherent and incoherent diffractive vector meson production at high energy including event-by-event fluctuations of the proton density profile. Large geometric fluctuations are found to be necessary in order to describe simultaneously both coherent and incoherent cross section measured at HERA. The color charge and saturation scale fluctuations are shown to have small effect on incoherent cross section at large momentum transfer, which leads to a conclusion of existence of strong event-by-event geometric fluctuations of the proton density profile.