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arXiv · hep-ph/0109104

Consistent Treatment of Soft and Hard Processes in Hadronic Interactions

F. M. Liu·H. J. Drescher·S. Ostapchenko·T. Pierog·K. Werner
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Abstract

The QCD improved parton model is a very successful concept to treat processes in hadronic interactions, whenever large partonic transverse momenta are involved. However, cross sections diverge in the limit p_T -> 0, and the usual treatment is the definition of a lower cutoff p_T_min, such that processes with a smaller p_T -- so-called soft processes -- are simply ignored, which is certainly not correct for example at RHIC energies. A more consistent procedure amounts to introduce a technical parameter Q_0^2, referred to as soft virtuality scale, which is nothing but an artificial borderline between soft and hard physics. We will discuss such a formalism, which coincides with the improved parton model for high p_T processes and with the phenomenological treatment of soft scattering, when only small virtualities are involved. The most important aspect of our approach is that it allows to obtain a smooth transition between soft and hard scattering, and therefore no artificial dependence on a cutoff parameter should appear.

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F. M. Liu, H. J. Drescher, S. Ostapchenko, T. Pierog, K. Werner. 2001-09-12. Consistent Treatment of Soft and Hard Processes in Hadronic Interactions. https://doi.org/10.1088/0954-3899%2F28%2F10%2F306

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