title: Ballistic protons in incoherent exclusive vector meson production as a measure of rare parton fluctuations at an electron-ion collider.
abstract: We argue that the proton multiplicities measured in Roman pot detectors at an electron ion collider can be used to determine centrality classes in incoherent diffractive scattering. Incoherent diffraction probes the fluctuations in the interaction strengths of multiparton Fock states in the nuclear wave functions. In particular, the saturation scale that characterizes this multiparton dynamics is significantly larger in central events relative to minimum bias events. As an application, we study the centrality dependence of incoherent diffractive vector meson production. We identify an observable which is simultaneously very sensitive to centrality triggered parton fluctuations and insensitive to details of the model.
authors.affiliation: Department of Physics, University of Jyväskylä, P.O. Box 35, 40014 University of Jyväskylä, Finland.|Helsinki Institute of Physics, P.O. Box 64, 00014 University of Helsinki, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Lappi
authors.affiliation: Department of Physics, University of Jyväskylä, P.O. Box 35, 40014 University of Jyväskylä, Finland.
authors.forename: H
authors.initials: H
authors.lastname: Mäntysaari
authors.affiliation: Building 510A, Physics Department, Brookhaven National Laboratory, Upton, New York 11973, USA.
authors.forename: R
authors.initials: R
authors.lastname: Venugopalan