Measurement of diffraction dissociation cross sections at sqrt(s)=7 TeV at the LHC

Results are presented for the single- and double-diffractive cross sections in pp collisions at $\sqrt{s}=7$ TeV at the LHC using the CMS detector. The differential SD cross section is measured as a function of $\xi$, the forward momentum loss of the incoming proton, for $-5.5<\log_{10}\xi<-2.5$. The differential DD cross section is measured using events for which one hadronic system is detected in the central detector ($12 \lesssim M_X \lesssim 394$ GeV) and the other one in the CASTOR calorimeter ($3.2 \lesssim M_Y \lesssim 12$ GeV), as a function of $\xi_{X}=M_X^2/s$ for $-5.5<\log_{10}\xi_X<-2.5$. The DD cross section is also measured differentially as a function of the width of the central pseudorapidity gap, $\Delta\eta$, for $\Delta\eta>3$ and $M_X, M_Y>10$ GeV. In addition, the inclusive differential cross section for events with a forward rapidity gap ($\mathrm{d}\sigma / \mathrm{d}\Delta\eta^{F}$) is measured over $\Delta\eta^{F}$ = 8.4 units of pseudorapidity. Measurements are compared to results from other experiments and to theoretical predictions.