PUB - Publikationen an der Universität Bielefeld

We consider the problem of internal particle state transformation, which is abound state of several constituents, from the particle's rest frame to thesystem in which this particle is relativistic. It is assumed that in the restframe of the composite particle, its internal state can be considered in thenonrelativistic approximation. It is shown, that this internal state isunchanged during the transition from one reference frame to another. Namely,given the particle is spherically symmetric in the rest frame, it remainsspherically symmetric in any other reference frame, and does not undergoLorentz contraction along the direction of motion of moving reference framewith respect to the rest frame. We discuss a possible application of theseresults to the description of hadron-hadron scattering, considering hadrons asa bound states of quarks.