On non-perturbative effects in the jet physics

We consider quark scattering off nonperturbative gluonic fields in the vacuum and its impact on the hadronic final state in the e+e- -annihilation. A conservative estimate gives a non-perturbative p approx. = 1 GeV. The modification of the final state survives even at an arbitrary high energy, where the corrections to the total cross-section die away. We also argue that the coupling constant extracted from the perturbative treatment of the jet phenomenology can well be different from that governing the correction to sigmasub(tot). (orig.)