Summary of Working Group B: Diffraction and Vector Mesons

The understanding of diffractive lepton-hadron or hadron-hadron interactions at high energies, where at least one of the beam hadrons stays intact and loses only a small fraction of its incident momentum, still represents one of the main challenges in Quantum Chromodynamics. Diffraction is being extensively studied both at HERA and the TEVATRON, and there is a growing community planning to continue this research at the LHC. The current experimental data as well as future plans have been reviewed during the sessions in Working Group B, where in total 21 experimental talks were presented. There were 19 theoretical talks, 11 of which dealt with the topic of saturation. In the following, contributions will be summarised which cover diffraction at HERA (section 2) and the TEVATRON (section 3), vector meson production and DVCS (section 4), the phenomenology of saturation (section 5), and future experimental opportunities (section 6).