Can Baryon Stopping Be Understood within a Hadronic Transport Approach

The changing shape of the rapidity spectrum of net protons over the SPS energy range is still lacking theoretical understanding. In this work, a model for string excitation and string fragmentation is implemented for the description of high energy collisions within a hadronic transport approach. The free parameters of the string model are tuned to reproduce the experimentally measured particle production in proton-proton collisions. With the fixed parameters we advance to calculations for heavy ion collisions, where the shape of the proton rapidity spectrum changes from a single peak to a double peak structure with increasing beam energy in the experiment. We present calculations of proton rapidity spectra at different SPS energies in heavy ion collisions. Qualitatively, a good agreement with the experimental findings is obtained. In a future work, the formation process of string fragments will be studied in detail aiming to quantitatively reproduce the measurement.

Rapidity dispersion analysis of individual events in proton–nucleus interactions at 70 GeV

An analysis of the dispersion parameter of the rapidity spectrum of particles in individual events in 70 GeV proton–nucleus interactions has been considered. Application of such a method of analysis of the interactions in photographic emulsions permits us to identify the clusters produced in such reactions.