[en] A certain regime of phase space (close to the edge) is found where a 'direct' production of pairs in a hard collision of partons (e.g. qanti q→e⁺e^-) dominates the 'indirect' one which proceeds through a sequence of steps. A striking effect is predicted for the hadron/lepton pair production ratio which should drop to zero there, if hadrons are produced indirectly through parton decays. In the same kinematic regime also a new type of parton process, namely qanti q→γγ may become accessible experimentally. This regime is also recommended for further search of heavy resonances. (Auth.)