Abstract (data abstract)

The dynamics of isolated-photon plus two-jet production in pp collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset corresponding to an integrated luminosity of 36.1 fb−1. Cross sections are measured as functions of a variety of observables, including angular correlations and invariant masses of the objects in the final state, γ+jet+jet. Measurements are also performed in phase-space regions enriched in each of the two underlying physical mechanisms, namely direct and fragmentation processes. The measurements cover the range of photon (jet) transverse momenta from 150 GeV (100 GeV) to 2 TeV. The tree-level plus parton-shower predictions from SHERPA and PYTHIA as well as the next-to-leading-order QCD predictions from SHERPA are compared with the measurements. The next-to-leading-order QCD predictions describe the data adequately in shape and normalisation except for regions of phase space such as those with high values of the invariant mass or rapidity separation of the two jets, where the predictions overestimate the data. The photon is required to have a transverse energy above 150 GeV and absolute value of pseudorapity |etaGamma|<2.37, excluding the region 1.37<|etaGamma|<1.56. The photon isolation is ensured by requiring the transverse energy around a cone of radius R=0.4 around the photon to be less than (10 + 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 DeltaR =0.4 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). At parton level it is the sum of transverse energy from all coloured partons in a cone of size DeltaR =0.4 around the photon direction. Particle-level jets are reconstructed with the anti-kt algorithm with R=0.4 using all stable final-state particles as input; muons, neutrinos and particles frompile-up activity are excluded. Jets are required to have a transverse momentum larger than 100 GeV in the rapidity region |yjet|<2.5 and to not be closer to the photon than DeltaRgamma_jet<=0.8 in the eta-phi plane. 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 76 independent components: starting from the one labelled RESOLUTION_MATERIALCALO__1down,RESOLUTION_MATERIALCALO__1up until the one labelled PH_SCALE_LEAKAGEUNCONV__1down,PH_SCALE_LEAKAGEUNCONV__1up. Each of the 76 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 the given observable. As a result, providing the positive and negative uncertainties as such would mean that the correlation between different observable 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 all tables: 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 observable 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 observable bins (for the same component). For example, for the first component: the upper entry corresponds to the sistematic uncertainty due to RESOLUTION_MATERIALCALO__1down (first part of the label) and the lower entry corresponds to the sistematic uncertainty due to RESOLUTION_MATERIALCALO__1up (second part of the label). The analogous strategy has been followed for the 87 components of the jet energy scale (JES).

Table 1

Data from Figures 4a

10.17182/hepdata.101751.v1/t1

Measured cross sections for isolated-photon plus two-jet production as functions of $E_{\mathrm{T}}^{\gamma}$ for the total phase-space. The predictions from Sherpa...
Table 2

Data from Figures 4b

10.17182/hepdata.101751.v1/t2

Measured cross sections for isolated-photon plus two-jet production as functions of $p_{\mathrm{T}}^{\textrm{jet}}$ for the total phase-space. The predictions from Sherpa...
Table 3

Data from Figures 4c

10.17182/hepdata.101751.v1/t3

Measured cross sections for isolated-photon plus two-jet production as functions of $|y^{\textrm{jet}}|$ for the total phase-space. The predictions from Sherpa...
Table 4

Data from Figures 4d

10.17182/hepdata.101751.v1/t4

Measured cross sections for isolated-photon plus two-jet production as functions of $\Delta y^{\gamma-\textrm{jet}}$ for the total phase-space. The predictions from...
Table 5

Data from Figures 4e

10.17182/hepdata.101751.v1/t5

Measured cross sections for isolated-photon plus two-jet production as functions of $\Delta \phi^{\gamma-\textrm{jet}}$ for the total phase-space. The predictions from...
Table 6

Data from Figures 5a

10.17182/hepdata.101751.v1/t6

Measured cross sections for isolated-photon plus two-jet production as functions of $\Delta y^{\textrm{jet}-\textrm{jet}}$ for the total phase-space. The predictions from...
Table 7

Data from Figures 5b

10.17182/hepdata.101751.v1/t7

Measured cross sections for isolated-photon plus two-jet production as functions of $\Delta \phi^{\textrm{jet}-\textrm{jet}}$ for the total phase-space. The predictions from...
Table 8

Data from Figures 5c

10.17182/hepdata.101751.v1/t8

Measured cross sections for isolated-photon plus two-jet production as functions of $m^{\textrm{jet}-\textrm{jet}}$ for the total phase-space. The predictions from Sherpa...
Table 9

Data from Figures 5d

10.17182/hepdata.101751.v1/t9

Measured cross sections for isolated-photon plus two-jet production as functions of $m^{\gamma-\textrm{jet}-\textrm{jet}}$ for the total phase-space. The predictions from Sherpa...
Table 10

Data from Figures 6a

10.17182/hepdata.101751.v1/t10

Measured cross sections for isolated-photon plus two-jet production as functions of $E_{\mathrm{T}}^{\gamma}$ for the fragmentation-enriched phase-space. The predictions from Sherpa...
Table 11

Data from Figures 6b

10.17182/hepdata.101751.v1/t11

Measured cross sections for isolated-photon plus two-jet production as functions of $p_{\mathrm{T}}^{\textrm{jet}}$ for the fragmentation-enriched phase-space. The predictions from Sherpa...
Table 12

Data from Figures 6c

10.17182/hepdata.101751.v1/t12

Measured cross sections for isolated-photon plus two-jet production as functions of $|y^{\textrm{jet}}|$ for the fragmentation-enriched phase-space. The predictions from Sherpa...
Table 13

Data from Figures 6d

10.17182/hepdata.101751.v1/t13

Measured cross sections for isolated-photon plus two-jet production as functions of $\Delta y^{\gamma-\textrm{jet}}$ for the fragmentation-enriched phase-space. The predictions from...
Table 14

Data from Figures 6e

10.17182/hepdata.101751.v1/t14

Measured cross sections for isolated-photon plus two-jet production as functions of $\Delta \phi^{\gamma-\textrm{jet}}$ for the fragmentation-enriched phase-space. The predictions from...
Table 15

Data from Figures 7a

10.17182/hepdata.101751.v1/t15

Measured cross sections for isolated-photon plus two-jet production as functions of $\Delta y^{\textrm{jet}-\textrm{jet}}$ for the fragmentation-enriched phase-space. The predictions from...
Table 16

Data from Figures 7b

10.17182/hepdata.101751.v1/t16

Measured cross sections for isolated-photon plus two-jet production as functions of $\Delta \phi^{\textrm{jet}-\textrm{jet}}$ for the fragmentation-enriched phase-space. The predictions from...
Table 17

Data from Figures 7c

10.17182/hepdata.101751.v1/t17

Measured cross sections for isolated-photon plus two-jet production as functions of $m^{\textrm{jet}-\textrm{jet}}$ for the fragmentation-enriched phase-space. The predictions from Sherpa...
Table 18

Data from Figures 7d

10.17182/hepdata.101751.v1/t18

Measured cross sections for isolated-photon plus two-jet production as functions of $m^{\gamma-\textrm{jet}-\textrm{jet}}$ for the fragmentation-enriched phase-space. The predictions from Sherpa...
Table 19

Data from Figures 8a

10.17182/hepdata.101751.v1/t19

Measured cross sections for isolated-photon plus two-jet production as functions of $E_{\mathrm{T}}^{\gamma}$ for the direct-enriched phase-space. The predictions from Sherpa...
Table 20

Data from Figures 8b

10.17182/hepdata.101751.v1/t20

Measured cross sections for isolated-photon plus two-jet production as functions of $p_{\mathrm{T}}^{\textrm{jet}}$ for the direct-enriched phase-space. The predictions from Sherpa...
Table 21

Data from Figures 8c

10.17182/hepdata.101751.v1/t21

Measured cross sections for isolated-photon plus two-jet production as functions of $|y^{\textrm{jet}}|$ for the direct-enriched phase-space. The predictions from Sherpa...
Table 22

Data from Figures 8d

10.17182/hepdata.101751.v1/t22

Measured cross sections for isolated-photon plus two-jet production as functions of $\Delta y^{\gamma-\textrm{jet}}$ for the direct-enriched phase-space. The predictions from...
Table 23

Data from Figures 8e

10.17182/hepdata.101751.v1/t23

Measured cross sections for isolated-photon plus two-jet production as functions of $\Delta \phi^{\gamma-\textrm{jet}}$ for the direct-enriched phase-space. The predictions from...
Table 24

Data from Figures 9a

10.17182/hepdata.101751.v1/t24

Measured cross sections for isolated-photon plus two-jet production as functions of $\Delta y^{\textrm{jet}-\textrm{jet}}$ for the direct-enriched phase-space. The predictions from...
Table 25

Data from Figures 9b

10.17182/hepdata.101751.v1/t25

Measured cross sections for isolated-photon plus two-jet production as functions of $\Delta \phi^{\textrm{jet}-\textrm{jet}}$ for the direct-enriched phase-space. The predictions from...
Table 26

Data from Figures 9c

10.17182/hepdata.101751.v1/t26

Measured cross sections for isolated-photon plus two-jet production as functions of $m^{\textrm{jet}-\textrm{jet}}$ for the direct-enriched phase-space. The predictions from Sherpa...
Table 27

Data from Figures 9d

10.17182/hepdata.101751.v1/t27

Measured cross sections for isolated-photon plus two-jet production as functions of $m^{\gamma-\textrm{jet}-\textrm{jet}}$ for the direct-enriched phase-space. The predictions from Sherpa...

Table 1

Table 2

Table 3

Table 4

Table 5

Table 6

Table 7

Table 8

Table 9

Table 10

Table 11

Table 12

Table 13

Table 14

Table 15

Table 16

Table 17

Table 18

Table 19

Table 20

Table 21

Table 22

Table 23

Table 24

Table 25

Table 26

Table 27

JSON

YAML

YODA

ROOT

CSV

Visualize

Ask a Question