modes (quarks, gluons or their preconfined bound states, condensates, blobs of hot matter...?) which can get excited by the gluon field of the impinging parton and radiate coherently if $n>1$. The necessary condition (\[ref\]) for the Cherenkov effect is satisfied for those gluons colliding with these internal modes whose energies are suitable for production of the states within these wings. Thus, the resonance amplitude is chosen for $F(E, 0^o)$ at comparatively low energies.

Second, it follows both from experiment and from dispersion relations that the real parts of hadronic amplitudes (and, consequently, $\Delta n$) become positive at very high energies as well. They are usually negative at intermediate energies. Their common feature is the rather high energy threshold above which the real parts of amplitudes become positive for all processes studied.

One can expect that these general features also hold for gluons as carriers of strong interaction forces. Then the gluonic Cherenkov effects can be observable in the two (low and high energy) regions.

Summarizing, the scenario, we have in mind, is as follows. Any parton, either belonging to a colliding nucleus or already scattered in the medium, can emit a gluon which traverses the nuclear medium. On its way, 