Observation of diffraction with the CMS experiment at the Large Hadron Collider

TL;DR

This paper reports the first observation of diffraction phenomena in proton-proton collisions at the LHC using the CMS detector, highlighting the detection of rapidity gaps and comparing results with simulation models.

Contribution

It provides the first evidence of inclusive diffraction and single-diffractive di-jet production at the LHC, expanding understanding of diffraction at high energies.

Findings

Evidence of inclusive diffraction at 0.9 and 2.36 TeV

Observation of single-diffractive di-jet production at 7 TeV

Comparison with PYTHIA6 and PHOJET models

Abstract

A clear evidence of inclusive diffraction observed by the CMS detector at the Large Hadron Collider in minimum bias events at $\sqrt{s}=$0.9 TeV, 2.36 TeV is presented. The observed diffractive signal is dominated by inclusive single-diffractive dissociation and can be identified by the presence of a Large Rapidity Gap that extends over the forward region of the CMS detector. A comparison of the data with Monte Carlo predictions provided by PYTHIA6 and PHOJET generators is given. In addition, first observation of the single-diffractive production of di-jets at $\sqrt{s}=$7 TeV is presented.