Central Diffraction in Proton-Proton Collisions at $\sqrt{s}=7$\,TeV with ALICE at LHC

TL;DR

This paper reports on the measurement of central diffraction events in proton-proton collisions at 7 TeV using the ALICE detector, employing a double-gap topology to identify diffractive processes and estimating background contributions.

Contribution

It introduces a novel method using double-gap topology to filter and analyze central-diffractive events at the LHC, with detailed background estimation.

Findings

Measured the double-gap event fraction as approximately 7.63×10^{-4}

Estimated background contributions from non-diffractive processes to be about 10%

Demonstrated the effectiveness of the double-gap topology in identifying diffractive events.

Abstract

A double-gap topology is used for filtering central-diffractive events from a proton-proton minimum-bias data sample at a centre-of-mass energy {$\sqrt{s}=7$\,TeV}. This topology is defined by particle activity in the ALICE central barrel and absence of particle activity outside. The fraction of events satisfying the double-gap requirement $R_{DG}$ is found to be {$7.63\pm0.02(stat.)\pm0.87(syst.)\times 10^{-4}$}. The background of this double-gap fraction is estimated by studying the contributions of non-diffractive, single- and double-diffractive dissociation processes as modelled by Monte Carlo event generators, and is found to be about 10%.