DOI: 10.17182/hepdata.134100.v1/t2
title: "Table 2" of "Inclusive-photon production and its dependence on photon isolation in $pp$ collisions at $\sqrt s=13$ TeV using 139 fb$^{-1}$ of ATLAS data"

description: Measured cross sections for inclusive isolated-photon production as a function of $E_{\rm T}^{\gamma}$ for $0.6&lt;|\eta^{\gamma}|&lt;0.8$ and photon isolation cone radius $R=0.4$.
description: CERN-LHC. Inclusive-photon production and its dependence on photon isolation in pp collisions at a centre-of-mass energy of 13 TeV using 139/fb of ATLAS data.

The cross sections are measured as functions of the photon transverse energy in different regions of photon pseudorapidity. The photons are required to be isolated by means of a fixed-cone method with two different cone radii (R=0.4 and 0.2). The dependence of the inclusive-photon production on the photon isolation is investigated by measuring the fiducial cross sections as functions of the isolation-cone radius and the ratios of the differential cross sections with different radii in different regions of photon pseudorapidity.


The photon is required to have a transverse energy above 250 GeV and absolute value of pseudorapity |etaGamma|&lt;2.37, excluding the region 1.37&lt;|etaGamma|&lt;1.56. The photon isolation is ensured by requiring the transverse energy around a cone of radius R=0.4 (or R=0.2) around the photon to be less than (4.8 + 0.0042 * ETGamma) [GeV]. At particle level it is the sum of transverse energy from all stable particles, except for muons, neutrinos and the photon itself, in a cone of size R =0.4 (or R=0.2) around the photon direction after the contribution from the underlying event is subtracted; the same subtraction procedure, based on the jet-area method, used on data is applied at the particle level (see the journal publication for details). 
 

Information about the bin-to-bin correlation of the systematic uncertainties. The following uncertainties are to be treated as uncorrelated bin-to-bin: sysPhotonID, sysBackgroundIsolation, sysBackgroundIsolationUpperLimit, sysBackgroundID, sysIsolationMC and sysMCstats. The systematic uncertainty due to the photon energy scale and resolution is partially correlated bin-to-bin and its decomposition into independent sources is given. In order to take into account properly the correlations due to the photon energy scale and resolution, see the information provided below.

The systematic uncertainty due to the photon energy scale (GES) and resolution (GER) is decomposed into 79 independent components: starting from the one labelled RESOLUTION_AF2 until the one labelled PH_SCALE_LEAKAGEUNCONV. Each of the 79 independent components has two variations (up and down). The uncertainties due to the up and down variations for each component are not necessarily symmetric and do not necessarily have different signs. Furthermore, the uncertainty for a given variation (up or down) of a given component can change sign bin to bin in Etgamma. As a result, providing the positive and negative uncertainties as such would mean that the correlation between different Etgamma bins and different measurements is lost. To avoid that loss and to provide the information on the correlation the following format is used for the uncertainties of each independent component in the tables 1 to 12 (for the differential cross sections), tables 25 to 30 (for the ratios of differential cross sections with different isolation radii) and tables 37 to 42 (for the fiducial integrated cross sections): for the upper entry of the uncertainty, the systematic uncertainty of the down variation is given, which can be either positive or negative, and is fully correlated with the upper entries of the other Etgamma bins (for the same component); for the lower entry of the uncertainty, the systematic uncertainty of the up variation is given, which can be either positive or negative, and is fully correlated with the lower entries of the other Etgamma bins (for the same component). For example, for the component labelled SCALE_L2GAIN: the upper entry corresponds to the sistematic uncertainty due to SCALE_L2GAIN__1down and the lower entry corresponds to the sistematic uncertainty due to SCALE_L2GAIN__1up.

Predictions for the differential cross sections (tables 13 to 24), ratios (tables 31 to 36) and fiducial integrated cross sections (tables 43 to 48) are given at NNLO QCD from the program NNLOJET using the CT18 PDF set at NNLO; for details, see the journal publication and the reference [19] (X. Chen et al., Single photon production at hadron colliders at NNLO QCD with realistic photon isolation, JHEP 08, 2022, 094). Four sources of uncertainty are considered and quoted separately for each bin in EtGamma, each region of |etaGamma| and each photon isolation radius: the uncertainty due to terms beyond NNLO (TheoryUncertEnvelopeScales), the uncertainty due to that in the PDFs (TheoryUncertPDF), the uncertainty due to that in alphas (TheoryUncertAlphas) and the uncertainty in the non-perturbative corrections (TheoryUncertNonPerturbative). The first one (TheoryUncertEnvelopeScales) was calculated at NNLO using the envelope of the 15-point scheme of variations of the renormalisation, factorisation and fragmentation scales (variations of two or more scales in opposite directions are excluded). The second one (TheoryUncertPDF) was calculated at NLO...