Journal of High Energy Physics > 2016 > 2016 > 11 > 1-52
Study of hard double-parton scattering in four-jet events in pp collisions at s = 7 $$ \sqrt{s}=7 $$ TeV with the ATLAS experiment
Source
Abstract
Inclusive four-jet events produced in proton-proton collisions at a centre-of-mass energy of s = 7 $$ \sqrt{s}=7 $$ TeV are analysed for the presence of hard double-parton scattering using data corresponding to an integrated luminosity of 37.3 pb−1, collected with the ATLAS detector at the LHC. The contribution of hard double-parton scattering to the production of four-jet events is extracted using an artificial neural network, assuming that hard double-parton scattering can be approximated by an uncorrelated overlaying of dijet events. For events containing at least four jets with transverse momentum pT ≥ 20 GeV and pseudorapidity |η| ≤ 4.4, and at least one having pT ≥ 42.5 GeV, the contribution of hard double-parton scattering is estimated to be fDPS = 0.092 − 0.011+ 0.005 (stat.) − 0.037+ 0.033 (syst.). After combining this measurement with those of the inclusive dijet and four-jet cross-sections in the appropriate phase space regions, the effective cross-section, σeff , was determined to be σeff = 14. 9 − 1.0+ 1.2 (stat.) − 3.8+ 5.1 (syst.) mb. This result is consistent within the quoted uncertainties with previous measurements of σeff , performed at centre-of-mass energies between 63 GeV and 8 TeV using various final states, and it corresponds to 21 − 6+ 7 % of the total inelastic cross-section measured at s = 7 $$ \sqrt{s}=7 $$ TeV. The distributions of the observables sensitive to the contribution of hard double-parton scattering, corrected for detector effects, are also provided.
Identifiers
journal e-ISSN : | 1029-8479 |
DOI | 10.1007/JHEP11(2016)110 |
Authors
The ATLAS collaboration
- Transilvania University of Brasov, Brasov, Romania
- University Politehnica Bucharest, Bucharest, Romania
- Universidade Nova de Lisboa, Dep Fisica and CEFITEC of Faculdade de Ciencias e Tecnologia, Caparica, Portugal
- Centre National de l’Energie des Sciences Techniques Nucleaires, Rabat, Morocco
- CERN, Geneva 23, Switzerland
B. Abbott
- University of Oklahoma, Homer L. Dodge Department of Physics and Astronomy, Norman, United States of America