Measurement of proton-proton inelastic scattering cross-section at √s=7 TeV

The TOTEM experiment at the LHC has measured the inelastic proton-proton cross-section at root s = 7 TeV in a beta* = 90 m run with low inelastic pile-up. The measurement was based on events with at least one charged particle in the T2 telescope acceptance of 5.3 < vertical bar eta vertical bar < 6.5 in pseudorapidity. Combined with data from the T1 telescope, covering 3.1 < vertical bar eta vertical bar < 4.7, the cross-section for inelastic events with at least one vertical bar eta vertical bar <= 6.5 final-state particle was determined to be (70.5 +/- 2.9) mb. This cross-section includes all central diffractive events of which maximally 0.25 mb is estimated to escape the detection of the telescopes. Based on models for low mass diffraction, the total inelastic cross-section was deduced to be (73.7 +/- 3.4) mb. An upper limit of 6.31 mb at 95% confidence level on the cross-section for events with diffractive masses below 3.4 GeV was obtained from the difference between the overall inelastic cross-section obtained by TOTEM using elastic scattering and the cross-section for inelastic events with at least one vertical bar eta vertical bar <= 6.5 final-state particle.