sPHENIX Conference Note: JET-2025-01

Title: Measurement of dijet imbalance (xJ) and acoplanarity (Δφ) in p+p collisions at √s = 200 GeV with the sPHENIX detector
Date: 2 April 2025
Tag: sPH-CONF-JET-2025-01
Document: Conference Note
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Figure 1 (Click to download high-resolution PDF Figures.)


Response matrix trained with PYTHIA-8 and the sPHENIX reconstruction chain.
Figure 2 (Click to download high-resolution PDF Figures.)


(Top) Δφ of reconstruction-level and truth-level PYTHIA-8 dijets in the leading pT1 bin 31.2 ≤ pT1 < 40.7 GeV selection. (Bottom) Correction factor applied to Δφ distribution in data.
Figure 3 (Click to download high-resolution PDF Figures.)


Total Systematic Uncertainties in xJ for three selections on pT1.
Figure 4 (Click to download high-resolution PDF Figures.)


Total systematic uncertainties of the three pT1 selection in Δφ.
Figure 5 (Click to download high-resolution PDF Figures.)


Total systematic uncertainties of the three pT2 selection in Δφ.
Figure 6 (Click to download high-resolution PDF Figures.)


Reconstruction level and unfolded xJ distributions of dijet events in three leading jet pT1 bins. Statistical uncertainties are shown as vertical lines and systematic uncertainties as filled boxes. Also shown are results from PYTHIA-8 and the ratio of the PYTHIA-8 truth distribution to the unfolded data distribution in the lower panels.
Figure 7 (Click to download high-resolution PDF Figures.)


Fully unfolded xJ final results. Statistical uncertainties are shown as vertical lines and systematic uncertainties as filled boxes. PYTHIA-8 and HERWIG-7.3 generator results are also shown.
Figure 8 (Click to download high-resolution PDF Figures.)


Δφ distributions for the three pT1 selections. Statistical uncertainties are shown as vertical lines and systematic uncertainties as filled boxes. PYTHIA-8 and HERWIG-7.3 generator results are also shown.
Figure 9 (Click to download high-resolution PDF Figures.)


Δφ distributions for the three pT2 selections with the middle pT1 selection. Statistical uncertainties are shown as vertical lines and systematic uncertainties as filled boxes. PYTHIA-8 and HERWIG-7.3 results are also shown.
Figure 10 (Click to download high-resolution PDF Figures.)


Δφ distributions for the three pT1 selections. Statistical uncertainties are shown as vertical lines and systematic uncertainties as filled boxes. PYTHIA-8 and HERWIG-7.3 generator results are also shown. Ratio of each generator to the data is shown on the bottom panel.
Figure 11 (Click to download high-resolution PDF Figures.)


Δφ distributions for the three pT2 selections with the middle pT1 selection. Statistical uncertainties are shown as vertical lines and systematic uncertainties as filled boxes. PYTHIA-8 and HERWIG-7.3 results are also shown. Ratio of each generator to the data is shown on the bottom panel.
Figure 12


Diagram of leading vec(pT1) and subleading vec(pT2) jets in the coordinate system used for the bisector method (reproduced from Ref. [29]).
Figure 13 (Click to download high-resolution PDF Figures.)


(Left) PYTHIA-8 truth dijet σ(pTψ) and σ(pTη) as a function of <pT> and (right) includes σ(pTψ) and σ(pTη) in reconstructed PYTHIA-8 jets and data.
Figure 14 (Click to download high-resolution PDF Figures.)


(top) Jet energy resolution in data and simulation derived form the bisector method as a function of average pT with fits and the JER function retrieved from simulation based calibration. (Bottom) The ratio of each average pT bin in Data and MC as well as the ratio of the fit to the data to the calibration result of the JER function.