Measurement of diffractive dissociation cross sections in pp collisions at s =7TeV

Measurements of diffractive dissociation cross sections in pp collisions at s√ =7  TeV are presented in kinematic regions defined by the masses M_X and M_Y of the two final-state hadronic systems separated by the largest rapidity gap in the event. Differential cross sections are measured as a function of ξ_X =M^2_X/s in the region −5.5 3, log(10)M_X >1.1, and log_(10)M_Y >1.1, a region dominated by DD. The cross sections integrated over these regions are found to be, respectively, 2.99±0.02(stat)^(+0.32)_(−0.29)(syst)  mb, 1.18±0.02(stat)±0.13(syst)  mb, and 0.58±0.01(stat)^(+0.13)_(−0.11)(syst)  mb, and are used to extract extrapolated total SD and DD cross sections. In addition, the inclusive differential cross section, dσ/dΔ_η^F, for events with a pseudorapidity gap adjacent to the edge of the detector, is measured over Δ_η^F =8.4 units of pseudorapidity. The results are compared to those of other experiments and to theoretical predictions and found compatible with slowly rising diffractive cross sections as a function of center-of-mass energy.