Hard diffractive electroproduction, transverse momentum distribution and QCD vacuum structure

الأصل · EN

We study the impact of the "intrinsic" hadron transverse momentum on the pre-asymptotic behavior of the diffractive electroproduction of longitudinally polarized ρ-meson. Surprisingly, we find the onset of the asymptotic regime in this problem to be rather low, Q² 10 GeV² where power corrections due to the transverse momentum do not exceed 20 % in the amplitude. This drastically contrasts with exclusive amplitudes where the asymptotics starts at much higher Q² = 50 - 100 GeV². The sources of such unexpected behavior are traced back to some general (the quark-hadron duality) as well as more silent (properties of higher dimensional vacuum condensates) features of QCD.