Finite formation time of hadrons: the QGP signatures

In order to investigate the possible emergence of guark-gluon plasma, it is necessary to understand the properties of multiparticle production mechanisms in a more simple case than in relativistic collisions of heavy ions. The purpose of this article is to discuss some problems of the role of zone formation effectwhich are under active investigation nowadays. The formation length of hadron from particle-nucleus collision is derived and compared with those from relativistic ion collisions.