Observation of a Diffractive Contribution To Dijet Production in Proton-Proton Collisions at Root S = 7 Tev

Abstract

The cross section for dijet production in proton-proton collisions at root s = 7 TeV is presented as a function of (xi) over tilde, a variable that approximates the fractional momentum loss of the scattered proton in single-diffractive events. The analysis is based on an integrated luminosity of 2.7 nb(-1) collected with the CMS detector at the LHC at low instantaneous luminosities, and uses events with jet transverse momentum of at least 20 GeV. The dijet cross section results are compared to the predictions of diffractive and non-diffractive models. The low-(xi) over tilde data show a significant contribution from diffractive dijet production, observed for the first time at the LHC. The associated rapidity gap survival probability is estimated. DOI: 10.1103/PhysRevD.87.012006