Generalized counting rule for hard exclusive processes

We derive a generalized counting rule for hard exclusive processes involving parton orbital angular momentum and hadron helicity flip. We start with a systematic way to enumerate the Fock components of a hadronic light-cone wave function with n partons and orbital angular momentum projection l(z). We show that the wave-function amplitude psi(n)(x(i),k(iperpendicular to),l(zi)) has a leading behavior 1/(k(perpendicular to)(2))([n+parallel tol)(z)parallel to+min(n(')+parallel tol(z)(')parallel to)]/2-1 when all parton transverse momenta are uniformly large, where n(') and l(z)(') are the number of partons and orbital angular momentum projection, respectively, of an amplitude that mixes under renormalization. Besides the generalized counting rule, the result can be used as a constraint in modeling the hadronic light-cone wave functions.