Generalized Parton Distributions in Terms of Light-cone Wave Functions

The light-cone expansion is constructed by quantizing QCD at fixed lightcone time τ = t + z and forming the invariant light-cone Hamiltonian: H LC = P +P− − P 2 ⊥ where P± = P 0 ± P . The proton state, for example, satisfies: H LC |ψp〉 = M p |ψp〉. The expansion of the proton eigensolution |ψp〉 on the color-singlet B = 1, Q = 1 eigenstates {|n〉} of the free Hamiltonian H LC (g = 0) gives the light-cone Fock expansion : ∣∣∣ψp(P+, P⊥)〉 = ∑