Lorentz invariance relations among parton distributions revisited

Abstract

We revisit the derivation of the so-called Lorentz invariance relations between parton distributions. In the most important cases these relations involve twist-3 and transverse momentum dependent parton distributions. It is shown that these relations are violated if the path-ordered exponential is taken into account in the quark correlator.

Comments: 4 pages, minor changes, to appear in Phys. Lett. B