Violation of Sum Rules for Twist-3 Parton Distributions in QCD
نویسندگان
چکیده
Sum rules for twist-3 distributions are reexamined. Integral relations between twist-3 and twist-2 parton distributions suggest the possibility for a δ-function at x = 0. We confirm and clarify this result by constructing hL and h 3 L (quark-gluon interaction dependent part of hL) explicitly from their moments for a one-loop dressed massive quark. The physics of these results is illustrated by calculating hL(x,Q ) using light-front time-ordered pQCD to O(αS) on a quark target. A δ(x) term is also found in e(x,Q), but not in gT (x,Q), to this order in O(αS).
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