Diffractive physics at the LHC

TOTEM is an experiment dedicated to the measurement of the total cross section, elastic scattering and diffraction dissociation at the Large Hadron Collider (LHC) which is now being built at CERN. The total cross section will be measured with the luminosity independent method based on the simultaneous measurement of low momentum transfer elastic scattering and of the rate of inelastic interactions with fully inclusive trigger. Elastic scattering events will be detected with the Roman pot technique using a suitable optics obtained by properly tuning the quadrupoles in the intersection region. The system of dipoles foreseen in the intersection region to first combine and then separate the proton beams will be used to measure the momentum of the protons which are diffractively scattered.