Measurements of the elastic, inelastic and total $pp$ cross sections with the ATLAS, CMS and TOTEM detectors

The total pp cross sections is a fundamental property of the strong interaction which can not be calculated in perturbative QCD but only described based on phenomenological models. The ATLAS and CMS collaborations have recently measured the total inelastic proton-proton cross section at 13 TeV centre-of-mass energy in special data sets with a low interaction probability per bunch crossing. A more precise measurement of the total pp cross section as well as elastic and inelastic contributions can be extracted from a measurement of the differential elastic cross section using the optical theorem. The TOTEM and ATLAS collaborations have collected elastic data in dedicated runs with high beta* optics at 8 TeV centre-of-mass energy with Roman Pot detectors in order to perform this measurement. From the extrapolation of the differential elastic cross section to t=0, using the optical theorem, the total cross section is extracted. In addition the nuclear slope of the elastic t-spectrum and the total elastic and inelastic cross sections are determined.