  An analytically calculable model has been proposed recently for the
simultaneous description of particle spectra and correlations, which is able to
explain in a natural manner the $m_t$ scaling of the radius parameters of the
Bose--Einstein correlation functions. We present here preliminary results on
fitting this model to data sampled by NA44 collaboration in central S + Pb
reactions at CERN SPS, which indicate that both pions and kaons freeze-out at a
surprisingly low temperature of T approximately 108 MeV.
