Structure Function Theory Summary

A bonus from the FL measurement was the need to run HERA at a lower energy, which will eventually provide a measurement of the energy-dependence of the total cross section for photoproduction (see Aharon Levy’s talk). This can be compared with predictions from Donnachie/Landshoff, or your personal favorite model for total cross sections. This old-fashioned physics may transition to new non-perturbative physics at LHC, where the interaction range in impact parameter receives a contribution from the Regge-expansion of the pomeron that is for the first time comparable to the range coming from the intrinsic proton size.