Measurement of inelastic, single and double diffraction cross sections in proton-proton collisions at LHC with ALICE

Submission Date: 
12/09/2012
Article Information
Submission Form
System: 
p-p
Energy: 
900 GeV
Energy: 
2.76 TeV
Energy: 
7 TeV
Abstract Plain Text: 

 

 

Measurements of basic cross sections characterizing proton-proton collisions at LHC energies were carried out with the ALICE detector.

Beam properties determined with van der Meer scans, combined with a detector simulation validated with data on inclusive particle production in minimum bias triggers, led to measurements of inelastic cross sections: sINEL = 62.2 ± 1.7 (model) ± 2.0 (luminosity) mb and 73.2 ± 1.1 (model) ± 2.6 (luminosity) mb, at √s = 2.76 and 7 TeV, respectively.

Relative rates of diffractive processes with respect to all inelastic collisions were obtained from a study of gaps in particle pseudorapidity distributions:
– Single diffraction (MX < 200 GeV/c2), sSD/sINEL = 0.215 ± 0.03 (syst.), 0.187 ± 0.055 (syst.) and 0.207 ± 0.04 (syst.), respectively at √s = 0.9, 2.76 and 7 TeV;
– Double diffraction (Δη > 3), sDD/sINEL = 0.108 ± 0.03 (syst.), 0.125 ± 0.05 (syst.) and 0.124 ± 0.035 (syst.), respectively at √s = 0.9, 2.76 and 7 TeV.

Single and double diffractive cross sections were obtained, combining relative rates of diffraction with inelastic cross sections.

These results are compared to previous measurements at proton-antiproton and proton-proton colliders, to other measurements at LHC, as well as to theoretical models.