Measurement of the total cross section of pp collisons at sqrt(s)=7 TeV from elastic scattering with the ATLAS detector
Résumé
The ATLAS measurement of the total p-p cross section at the LHC at sqrt(s)= 7 TeV is
presented. In a special LHC run with high betastar beam optics corresponding to an integrated
luminosity of 80 inverse microbarn the elastic scattering process is measured in the range of
the momentum transverse t from -t=0.0025 GeVˆ{2} to -t=0.38 GeVˆ{2} with the ALFA
detector of ATLAS. From the extrapolation of the differential elastic cross section to t=0
GeVˆ2 using the optical theorem the total cross section sigma(pp->X) is extracted with the
luminosity-dependent method. In addition the nuclear slope of the elastic t-spectrum, the
total elastic and inelastic cross sections are determined.