Observation of diffraction and measurement of the forward energy flow with the CMS detector

TL;DR

This paper reports the first observation of inclusive diffraction at the LHC using the CMS detector at multiple energies, and measures forward energy flow, comparing results with Monte Carlo simulations.

Contribution

It presents the first observation of inclusive diffraction at the LHC with CMS and provides measurements of forward energy flow across different energies.

Findings

Diffractive events identified by Large Rapidity Gaps.

Forward energy flow measured at multiple energies.

Data compared with PYTHIA and PHOJET simulations.

Abstract

The observation of inclusive diffraction with the CMS detector at the LHC is presented for centre-of-mass energies \sqrt s = 0.9 TeV and 2.36 TeV. Diffractive events are selected by the presence of a Large Rapidity Gap in the forward region of the CMS detector and uncorrected data are compared with Monte Carlo simulations based on the event generators PYTHIA and PHOJET. The measurement of the forward energy flow, in the pseudorapidity region 3.15 < |\eta| < 4.9, is also presented at \sqrt s = 0.9 TeV, 2.36 TeV and 7 TeV. Uncorrected data are compared with Monte Carlo simulations based on PYTHIA.