# 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.