Thermal hadron production in Si-Au collisions
  The most abundantly produced hadron species in $Si\!-\!Au$ collisions at the BNL-AGS (nucleons, pions, kaons, antikaons and hyperons) are shown to be in accord with emission from a thermal resonance gas source of temperature $T\simeq 110$ MeV and baryochemical potential $\mu_B \simeq 540$ MeV, corresponding to about 1/3 standard nuclear density. Our analysis takes the isopin asymmetry of the initial state fully into account. 
J. Cleymans, D. Elliott, H. Satz and R. L. Thews