A non-perturbative effect in deep inelastic scattering

Abstract The HERA data at large Q 2 and small- x investigate large distances on the light-cone . At such large distances the scattered quarks can maintain their colour identity, i.e. they remain colour non-singlets and confined, by polarizing the vacuum as they transfer energy to it. We calculate the probability for the creation of quark-antiquark pairs from the polarized QCD vacuum and their contribution to the structure function.