Pionisation in GeV to TeV hadron-nucleus and nucleus-nucleus interaction - coherent or chaotic?

A detailed study is reported of coherent and chaotic production of pions in hadron-nucleus interactions over a wide range of incident energies, viz., 200 GeV to 9.5 TeV, and in nucleus-nucleus interactions at 2.1 to 4.5 GeV/c/n. The experimental multiplicity distributions in different overlapping pseudorapidity bins was matched with the Poissonian and Chaotic form. Disagreement with Poissonian distributions was strongly indicated by the data in all cases, and for low-energy hadron-nucleus interactions and nucleus-nucleus interactions, the central-most region is most Chaotic while for hadron-nucleus interactions at comparatively high energy, the multiplicity distribution is more or less Chaotic in all bins. (author)