Measurement of diffraction dissociation cross sections in pp collisions at sqrt(s) = 7 TeV

TL;DR

This paper reports precise measurements of diffractive dissociation cross sections in proton-proton collisions at 7 TeV, covering various kinematic regions and providing data that support models of slowly rising diffractive cross sections with energy.

Contribution

It provides the first detailed measurements of diffractive dissociation cross sections in specific kinematic regions at 7 TeV, including differential and integrated cross sections, and compares them with theoretical predictions.

Findings

Cross sections for SD and DD processes are quantified.

Results support models of slowly increasing diffractive cross sections with energy.

Data are compatible with previous experiments and theoretical models.

Abstract

Measurements of diffractive dissociation cross sections in pp collisions at sqrt(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 xi[X]= M[X]^2/s in the region -5.5 < log[10]xi[X] < -2.5, for log[10]M[Y] < 0.5, dominated by single dissociation (SD), and 0.5 < log[10]M[Y] < 1.1, dominated by double dissociation (DD), where M[X] and M[Y] are given in GeV. The inclusive pp cross section is also measured as a function of the width of the central pseudorapidity gap Delta eta for Delta eta > 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 total SD and DD cross sections. In addition, the inclusive differential cross section, d sigma /d Delta eta[F], for events with a pseudorapidity gap adjacent to the edge of the detector, is measured over Delta eta[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.