Speaker
Maciej Marek Trzebinski
(Polish Academy of Sciences)
Description
The total pp cross section 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 collaboration has explored the
total proton-proton cross section, using measurements of the total inelastic
proton-proton cross sections and of the diffractive part of the inelastic
cross section in special data sets taken with low beam currents. The
measurements have been performed at center of mass energies of 7TeV and 13TeV,
using special forward scintillators or the calorimeters. Studies of the
production of di-jets accompanied by a large rapidity gap are presented,
which is also used to estimate the "gap survival probability" in
hadron-hadron collisions. Finally, a measurement of exclusive production of
dileptons in 7 TeV pp collisions is presented. The results show significant
deviations from the pure QED prediction, which can be explained by photon
coherence and proton rescattering effects.
The total cross section can be also extracted from a measurement of the
differential elastic cross section using the optical theorem. The ATLAS
Collaboration has collected 0.5 /nb of elastic data in a dedicated run with
high beta* optics at 8 TeV centre-of-mass energy with the ALFA Roman Pot
detector in order to perform this measurement.
Primary author
Elizaveta Shabalina
(University of Gottingen)
