Ce. Carlson et M. Chachkhunashvili, VECTOR POLARIZATION AT HIGH MOMENTUM-TRANSFERS IN QCD, Physical review. D. Particles and fields, 45(7), 1992, pp. 2555-2558
We show in the context of perturbative QCD that all single transverse
vector polarizations or analyzing powers are zero in the high-momentum
-transfer limit. The proof depends on hadron helicity conservation, wh
ich applies to exclusive processes that are dominated by a short-dista
nce reaction mechanism. Some comments are made about the available dat
a.