Deep inelastic scattering in formalism with wave functions of rest compound system

One of the most simple examples of interaction of compound systems: deep inelastic scattering of the point particle on hadron is considered. By choosing the compound particle (hadron) rest system the corresponding cross section is expressed in terms of more usual from the view point of nonrelativistic quantum mechanics wave functions of the rest bound state. A new variant of structure functions expansion into a series in terms of the coupling constant is suggested. Each therm of a series due to correct account of the energy conservation law in any order of the perturbation theory possess spectral property. Analysis in QCD shows that in the bound state rest system (P-vector=0) the pulse approximation though satisfies the requirements of scale invariance is insufficient for correct description of elastic limit xBj→1 by contrast to PZ→∞ system. It means that parton model is equivalent to pulse approximation only in PZ→∞ system. To obtain the leading in asymptotic region xBj→1 terms account of component interaction in the finite state is necessary. The simplicity and physical evidence of the wave functions are attained due to the seeming complication of calculations according to the perturbation theory