Measurement of dijet azimuthal decorrelations in $pp$ collisions at $\sqrt{s}=8$ TeV with the ATLAS detector and determination of the strong coupling

Abstract

A measurement of the rapidity and transverse momentum dependence of dijet azimuthal decorrelations is presented, using the quantity $R_{\Delta \varphi }$. The quantity $R_{\Delta \varphi }$ specifies the fraction of the inclusive dijet events in which the azimuthal opening angle of the two jets with the highest transverse momenta is less than a given value of the parameter $\Delta {\varphi }_{\max }$. The quantity $R_{\Delta \varphi }$ is measured in proton--proton collisions at $\sqrt{s}=$8 TeV as a function of the dijet rapidity interval, the event total scalar transverse momentum, and $\Delta {\varphi }_{\max }$. The measurement uses an event sample corresponding to an integrated luminosity of 20.2 fb${}^{-1}$ collected with the ATLAS detector at the CERN Large Hadron Collider. Predictions of a perturbative QCD calculation at next-to-leading order in the strong coupling with corrections for non-perturbative effects are compared to the data. The theoretical predictions describe the data in the whole kinematic region. The data are used to determine the strong coupling ${\alpha }_{\mathrm{S}}$ and to study its running for momentum transfers from 260 GeV to above 1.6 TeV. An analysis that combines data at all momentum transfers results in ${\alpha }_{\mathrm{S}}(m_Z)=0.1127_{-0.0027}^{+0.0063}$.

46 pages in total, author list starting page 30, 4 figures, 11 tables, submitted to Phys. Rev. D.. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2012-19

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Cited by in corpus (9)

• The Large Hadron-Electron Collider at the HL-LHC
• All master integrals for three-jet production at NNLO
• A first next-to-next-to-leading order study of three-jet production at the LHC
• Why ${\alpha }_s$ Cannot be Determined from Hadronic Processes without Simultaneously Determining the Parton Distributions
• Precision QCD Physics at the LHC
• Hard color-singlet exchange in dijet events in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Measurement of multijet azimuthal correlations and determination of the strong coupling in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Perturbative QCD predictions in fixed order for cross section ratios
• Limits on new strongly interacting matter from measurements of Transverse Energy-Energy Correlations at $\sqrt{s}=13$ TeV at the LHC