Inclusive single particle spectra and the strong thermodynamic bootstrap solution

The thermodynamical model was based so far on a bootstrap condition requiring asymptotic equality of the logarithms of the hadronic mass spectrum and of the level density of the fireballs, resulting in a family of exponential solutions, of which one was chosen on the basis of plausibility arguments. Through the work of Frautschi (1971), Frautschi and Hamer (1971) and of Nahm (1972), the bootstrap condition has been sharpened and now leads to a unique asymptotic solution slightly different from the one chosen before. The authors discuss in this paper the consequences of using this strong bootstrap solution in the thermodynamical model for particle production. If all other assumptions remain unmodified, the following changes occur: the decay chain of fireball becomes approximately manageable and is included in the analysis; scaling and limiting fragmentation hold exactly; the rapidity distribution has a central plateau; and multiplicities grow logarithmically. Numerical differences against the old version are, however, small even at ISR energies, where the predictions are compared with experimental data. (31 refs).