Study of dijet events with a large rapidity gap between the two leading jets in pp collisions at $\sqrt{s}$ = 7 TeV

Abstract

Events with no charged particles produced between the two leading jets are studied in proton-proton collisions at root s = 7 TeV. The jets were required to have transverse momentum p(T)(jet) > 40 GeV and pseudorapidity 1.5 < vertical bar eta(jet)vertical bar < 4.7, and to have values of eta(jet) with opposite signs. The data used for this study were collected with the CMSdetector during low-luminosity running at the LHC, and correspond to an integrated luminosity of 8 pb(-1). Events with no charged particles with p(T) > 0.2GeV in the interval -1 < eta < 1 between the jets are observed in excess of calculations that assume no color-singlet exchange. The fraction of events with such a rapidity gap, amounting to 0.5-1% of the selected dijet sample, is measured as a function of the pT of the second-leading jet and of the rapidity separation between the jets. The data are compared to previous measurements at the Tevatron, and to perturbative quantum chromodynamics calculations based on the Balitsky-Fadin-Kuraev-Lipatov evolution equations, including different models of the non-perturbative gap survival probability.Fonds pour la Formation a la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium)Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand)Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium)Mobility Plus program of the Ministry of Science and Higher EducationConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Ministry of Education, Youth and Sports (MEYS) of the Czech RepublicEuropean Research Council and Horizon Grant (European Union): 675440Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)