Recent Results of the Hadron Resonance Gas Model and the Chemical   Freeze-out of Strange Hadrons
  A detailed discussion of recent results obtained within the hadron resonance gas model with the multi-component hard core repulsion is presented. Among them there are the adiabatic chemical freeze-out criterion, the concept of separate chemical freeze-out of strange particles and the effects of enhancement and sharpening of wide resonances and quark gluon bags occurring in a thermal medium. These findings are discussed in order to strengthen the planned heavy-ion collision experimental programs at low collision energies. We argue, that due to found effects, at the center of mass collision energy 4-8 GeV the quark gluon bags may appear directly or in decays as new heavy resonances with the narrow width of about 50-150 MeV and with the mass above 2.5 GeV. 
K. A. Bugaev, A. I. Ivanytskyi, D. R. Oliinychenko, E. G. Nikonov, V.   V. Sagun and G. M. Zinovjev
hep-ph nucl-th