An extension of the Statistical Bootstrap Model to include Strangeness

We extend the Statistical Bootstrap Model (SBM) in order to describe hadronic systems which carry strangeness. We establish that the hadronic phase can exist only in a region of the three-dimensional space of temperature, up-down and strange chemical potentials, which is bounded by a critical critical surface. We first employ the usual version of the SBM, which corresponds to the value 2 of the exponent which determines the asymptotic fall-off of the mass spectrum and impose strangeness neutrality in order to obtain the relation between the temperature and the chemical potentials of the quarks. We find an unphysical behaviour of the strange chemical potential near the critical surface. Subsequently, we study another version of SBM where the value of the exponent equals 4 and we are led to a realistic as well as acceptable behaviour. In this case we are also able to relate the parameter of the model, the critical temperature at zero strange chemical potential) with the MIT bag constant B.