TNT Colloquium: Non-Gaussian color charge quantum fluctuations in the proton on the light front [NCSU]

A proton on the light front is described in terms of multi
parton states in Fock space. At moderate light-cone momentum fractions
x ~ 0.1 this is dominated by the three quark Fock state. The color
charge density per unit transverse area is measured by a quantum
mechanical operator rho corresponding to the large light cone
component of the color current expressed in terms of creation and
annihilation operators for quarks. I discuss matrix elements in the
proton of up to four rho operators. They show that fluctuations of the
color charge density are not Gaussian. I relate these correlators to
n-body Generalized Parton Distributions (GPDs) and discuss how they
can be probed in exclusive photon-proton scattering
processes. Specific examples include gamma + p --> J/Psi + p, which
involves the correlator of two rho, and gamma + p --> eta_c + p, which
involves the C-odd component of the correlator of three rho.