Inelastic proton cross section at 13 TeV with ATLAS

The recent measurement of the inelastic cross section at 13 TeV with the ATLAS detector is presented. Method of its calculation is based on the independent measurements of the rate of inelastic collisions and the LHC luminosity. The result of 79.3 $\pm$ 2.9 mb is obtained after extrapolation to the full phase space and is compared with a range of theoretical predictions. In addition, the fraction of diffractive events is estimated using two event selections. The low-luminosity data of total integrated luminosity of 60.1 $\mu$b$^{-1}$ recorded in June 2015 is used.