Phenomenological description of the gamma* p cross section at low Q2
  Low Q2 photon-proton cross sections are analysed using a simple, QCD-motivated parametrisation $\sigma_{\gamma^\star p}\propto 1/(Q^2+Q_0^2)$, which gives a good description of the data. The Q2 dependence of the gamma* p cross section is discussed in terms of the partonic transverse momenta of the hadronic state the photon fluctuates into. 
A. Rostovtsev (1), M.G. Ryskin (2), and R. Engel (3) ((1) ITEP,   Moscow, (2) Petersburg Nuclear Physics Institute, St. Pete...