Abstract
Documentation
FIG.1 Artificial Neural Network (ANN) output distribution normalized to unity of signal (red) and background (blue) PYTHIA MC templates, for one photon ET bin: 50< Eγ
T(GeV) <60 .FIG.2
Fits to the ANN distributions in bins of photon transverse energy for 30 < EγT(GeV) < 500.
ANN output distributions observed in the data (black points) and the distributions fit result given by the SUM of MC signal (red) and background (blue) templates scaled to TFractionFitter rates. The distributions fit result are normalized to data.
FIG.3 Signal fraction as a function of photon ET . The error bars represent the statistical errors and the azure bands represent the systematic errors.
FIG.4 Total systematic uncertainty and single contributions on the signal fraction (f γ ) as a function of photon ET.
FIG.5 Acceptance x Efficiency factors as a function of photon ET. The error bars represent the MC statistical errors and the azure bands represent the systematic errors.
FIG.6 Total systematic uncertainty and single contributions on the Acceptance x Efficiency factors as a function of photon ET.
For comparison we have used
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FIG.7 The measured γ + X cross section compared with three theoretical predictions: PYTHIA, SHERPA and MCFM. The vertical error bars show the statistical uncertainties, while the shaded areas show thesystematic uncertainties. The 6% luminosity uncertainty on the data is not included. A correction to account for extra activity (CUE) is applied to the MCFM theoretical predictions.
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FIG.8 The fractional systematic errors on the measured γ + X cross section. The continuous line is total systematic uncertainty while the dashed lines correspond to the single contribution.
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FIG.9 Ratio of the measured γ + X cross section to three theoretical predictions: PYTHIA (upper part), SHERPA (central part) and MCFM (bottom part). The vertical error bars show the statistical uncertainties, while the shaded areas show thesystematic uncertainties. The 6% luminosity uncertainty on the data is not included. A correction to account for extra activity (CUE) is applied to the MCFM theoretical predictions.
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FIG.10 Data points centered at 1 and Data/Theory ratio (lines) of the inclusive prompt photon cross section as a function of the photon transverse energy, EγT> , in the central ηγ region.The inner error bars on the data points show statistical uncertainties. The full error bars show statistical and systematic uncertainties added in quadrature. The 6% luminosity uncertainty on the data is not included. Pythia has been multiplied by a factor 1.5.
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FIG.11 From MCFM we can obtain predictions for the single sub-processes contribution. As expected, Compton scattering process dominates for photons with low transverse energies while the annihilation process dominates for high transverse energies.