Partecipanti: Prof. Per Grafstrom (CERN)
Abstract: After as short historical introduction to measurements of the total cross section in proton-proton and antiproton-proton scattering the close relation between the total cross section and elastic scattering will be highlighted. The importance of general and model independent approaches using the optical theorem and dispersion relations will be discussed. Sometime will be devoted to explain how dispersion relations can be used and have been used in the context of elastic scattering. Our own attempts to prepare the use of dispersion relations in relation to LHC data will also be discussed. The consequence of the recent published result from the TOTEM experiment will be brought up. In particular different scenarios of the energy dependence the total cross section and its impact on the real to imaginary part of the elastic scattering amplitude will be presented.