Diffraction dissociation in proton-proton collisions at $\sqrt{s}$ = 0.9   TeV, 2.76 TeV and 7 TeV with ALICE at the LHC
  The relative rates of single- and double- diffractive processes were measured with the ALICE detector by studying properties of gaps in the pseudorapidity distribution of particles produced in proton-proton collisions at $\sqrt{s}$ = 0.9 TeV, 2.76 TeV and 7 TeV. ALICE triggering efficiencies are determined for various classes of events, using a detector simulation validated with data on inclusive particle production. Cross-sections are determined using van der Meer scans to measure beam properties and obtain a measurement of the luminosity. 
M.G. Poghosyan (for the ALICE collaboration)
hep-ex