Speaker
Description
The TOTEM experiment, located at the interaction point 5 of the LHC, has measured the total, elastic and inelastic proton-proton cross sections in a centre-of-mass energy range from 2.76 to 13 TeV, mostly in dedicated fills with special beam optics. Most recently, TOTEM has performed a series of detailed measurements at √s = 13 TeV. The total, elastic and inelastic proton-proton cross-sections were determined using the luminosity-independent method based on the optical theorem. The elastic scattering was investigated in a wide range of the squared four-momentum transfer |t|. The study of Coulomb-nuclear interference region down to |t| ~ 8 x 10-4 GeV2 allowed in particular the first measurement of the ρ parameter at √s = 13 TeV, ρ being the ratio between the real and the imaginary part of the nuclear elastic scattering amplitude at t = 0. This measurement, combined with the TOTEM total cross-section results, led to the exclusion of all the models classified and published by the COMPETE Collaboration. The results obtained by TOTEM are indeed compatible with predictions of a colorless 3-gluon bound state exchange in the t-channel of proton-proton elastic scattering, as postulated by alternative theoretical models both in the Regge-like framework and in the modern QCD framework.
An overview of these measurements will be given.
