Dijet Azimuthal Decorrelations in pp Collisions at 7 TeV

Abstract

Measurements of dijet azimuthal decorrelations in pp collisions at a center-of-mass energy of 7 TeV using the CMS detector at the CERN LHC are presented. The analysis is based on an inclusive dijet event sample corresponding to an integrated luminosity of 2.9 $pb^{-1}$. The results are compared to predictions from perturbative QCD calculations and various Monte Carlo event generators. The dijet azimuthal distributions are found to be sensitive to initial-state gluon radiation.

Approved Plots from QCD-10-026 ( click on the plot to get the pdf version )

Normalized $\Delta\varphi_{dijet}$ distributions in several $p_{T}^{max}$ regions, scaled by the multiplicative factors given in the figure for easier presentation. The curves represent predictions from PYTHIA6, PYTHIA8, HERWIG++, and MADGRAPH. The error bars on the data points include statistical and systematic uncertainties.
Ratios of measured normalized $\Delta\varphi_{dijet}$ distributions to PYTHIA6, PYTHIA8, HERWIG++, and MADGRAPH predictions in several $p_{T}^{max}$ regions. The shaded bands indicate the total systematic uncertainty.
Normalized $\Delta\varphi_{dijet}$ distributions in several $p_{T}^{max}$ regions, scaled by the multiplicative factors given in the figure for easier presentation. The curves represent predictions from LO (dotted line) and NLO pQCD (solid line). Non-perturbative corrections have been applied to the predictions. The error bars on the data points include statistical and systematic uncertainties.

This plot is included in the arXiv version but not in the PRL version!

Ratios of measured normalized $\Delta\varphi_{dijet}$ distributions to NLO pQCD predictions with non-perturbative corrections in several $p_{T}^{max}$ regions. The error bars on the data points include statistical and systematic uncertainties. The effect on the NLO pQCD predictions due to $\mu_r$ and $\mu_f$ scale variations and PDF uncertainties, as well as the uncertainties from the non-perturbative corrections are shown.
Ratios of measured normalized $\Delta\varphi_{dijet}$ distributions to PYTHIA6 tune D6T with various values of $k_{ISR}$ in several $p_{T}^{max}$ regions. The shaded bands indicate the total systematic uncertainty.

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Responsible: CosminDragoiu
-- CosminDragoiu - 26-Jun-2011

Topic attachments
I Attachment History Action Size Date Who Comment
PDFpdf deltaPhi_data_over_MC.pdf r1 manage 16.7 K 2011-06-26 - 05:10 CosminDragoiu  
PNGpng deltaPhi_data_over_MC.png r1 manage 114.4 K 2011-06-26 - 05:24 CosminDragoiu  
PDFpdf deltaPhi_data_over_theory.pdf r1 manage 15.5 K 2011-06-26 - 05:38 CosminDragoiu  
PNGpng deltaPhi_data_over_theory.png r1 manage 75.2 K 2011-06-26 - 05:38 CosminDragoiu  
PDFpdf deltaPhi_data_ratio_ISR.pdf r1 manage 26.5 K 2011-06-26 - 05:40 CosminDragoiu  
PNGpng deltaPhi_data_ratio_ISR.png r1 manage 59.0 K 2011-06-26 - 05:40 CosminDragoiu  
PDFpdf deltaPhi_data_ratio_MC.pdf r1 manage 27.8 K 2011-06-26 - 05:36 CosminDragoiu  
PNGpng deltaPhi_data_ratio_MC.png r1 manage 66.4 K 2011-06-26 - 05:37 CosminDragoiu  
PDFpdf deltaPhi_data_ratio_theory.pdf r1 manage 20.8 K 2011-06-26 - 05:39 CosminDragoiu  
PNGpng deltaPhi_data_ratio_theory.png r1 manage 56.7 K 2011-06-26 - 05:39 CosminDragoiu  
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Topic revision: r2 - 2013-03-09 - JeffreyBerryhill
 
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