Multiplicity distributions at hadron colliders

A simple QCD-motivated effective model is investigated to describe the minimum bias data observed at various hadron colliders, especially for multiplicity distributions. We also extend the model by including multiple parton interactions, which becomes more significant as energy grows. We can fit quite well all the available data from ISR, UA1, UA5 and CDF with various pseudo-rapidity cuts. Despite the many experimental and theoretical uncertainties the level of agreement with observations is encouraging, and suggest that our effective model may provide an important guide to further theoretical and experimental investigations.