The expected and observed upper limits at 95\% CL on the production cross-section times branching ratio to two photons of the lightest KK graviton as a function of its mass for k/Mpl=0.10. For masses greater than 1000 GeV, pseudo-experiments are used to verify the expected and observed limits, and used in place of the asymptotic limit when differences are observed.

Expected and observed limits computed using asymptotic formulas as a function of the signal mass m_{X} and the relative width $\Gamma_{X}/m_{X}$ for the spin-0 resonance search.

Expected and observed limits computed using asymptotic formulas as a function of the signal mass m_{X} and the relative width $\Gamma_{X}/m_{X}$ for the spin-0 resonance search.

Expected and observed limits computed using asymptotic formulas as a function of the signal mass m_{G*} and k/Mpl for the spin-2 resonance search.

Expected and observed limits computed using asymptotic formulas as a function of the signal mass m_{G*} and k/Mpl for the spin-2 resonance search.

The expected and observed upper limits at 95\% CL on the fiducial cross-section times branching ratio to two photons of a spin-0 resonance as a function of its mass m_X. The decay width of the resonance is equal to 2% of m_X. For masses greater than 1000 GeV, pseudo-experiments are used to verify the expected and observed limits, and used in place of the asymptotic limit when differences are observed.

The expected and observed upper limits at 95\% CL on the fiducial cross-section times branching ratio to two photons of a spin-0 resonance as a function of its mass m_X. The decay width of the resonance is equal to 2% of m_X. For masses greater than 1000 GeV, pseudo-experiments are used to verify the expected and observed limits, and used in place of the asymptotic limit when differences are observed.

The expected and observed upper limits at 95\% CL on the fiducial cross-section times branching ratio to two photons of a spin-0 resonance as a function of its mass m_X. The decay width of the resonance is equal to 6% of m_X. For masses greater than 1000 GeV, pseudo-experiments are used to verify the expected and observed limits, and used in place of the asymptotic limit when differences are observed.

The expected and observed upper limits at 95\% CL on the fiducial cross-section times branching ratio to two photons of a spin-0 resonance as a function of its mass m_X. The decay width of the resonance is equal to 6% of m_X. For masses greater than 1000 GeV, pseudo-experiments are used to verify the expected and observed limits, and used in place of the asymptotic limit when differences are observed.

The expected and observed upper limits at 95\% CL on the fiducial cross-section times branching ratio to two photons of a spin-0 resonance as a function of its mass m_X. The decay width of the resonance is equal to 10% of m_X. For masses greater than 1000 GeV, pseudo-experiments are used to verify the expected and observed limits, and used in place of the asymptotic limit when differences are observed.

The expected and observed upper limits at 95\% CL on the fiducial cross-section times branching ratio to two photons of a spin-0 resonance as a function of its mass m_X. The decay width of the resonance is equal to 10% of m_X. For masses greater than 1000 GeV, pseudo-experiments are used to verify the expected and observed limits, and used in place of the asymptotic limit when differences are observed.

The expected and observed upper limits at 95\% CL on the production cross-section times branching ratio to two photons of the lightest KK graviton as a function of its mass for k/Mpl=0.01. For masses greater than 1000 GeV, pseudo-experiments are used to verify the expected and observed limits, and used in place of the asymptotic limit when differences are observed.

The expected and observed upper limits at 95\% CL on the production cross-section times branching ratio to two photons of the lightest KK graviton as a function of its mass for k/Mpl=0.01. For masses greater than 1000 GeV, pseudo-experiments are used to verify the expected and observed limits, and used in place of the asymptotic limit when differences are observed.

The expected and observed upper limits at 95\% CL on the production cross-section times branching ratio to two photons of the lightest KK graviton as a function of its mass for k/Mpl=0.05. For masses greater than 1000 GeV, pseudo-experiments are used to verify the expected and observed limits, and used in place of the asymptotic limit when differences are observed.

The expected and observed upper limits at 95\% CL on the production cross-section times branching ratio to two photons of the lightest KK graviton as a function of its mass for k/Mpl=0.05. For masses greater than 1000 GeV, pseudo-experiments are used to verify the expected and observed limits, and used in place of the asymptotic limit when differences are observed.

Diphoton invariant mass in the signal region using a binning based on the invariant mass resolution.

Diphoton invariant mass in the signal region using a binning based on the invariant mass resolution.

Diphoton invariant mass in the signal region binned in 1 GeV bins..

Diphoton invariant mass in the signal region binned in 1 GeV bins..

Effect of event selections on a NWA spin-0 and a spin-2 ($k/Mpl=0.01$) MC samples generated for m_X = 1 TeV and on the data. For the MC samples, the event yield is shown after applying event weights; for the data, the absolute yields are shown. The initial yields for data include a trigger preselection that is the OR of a list of single photon and diphoton triggers. The "2 $loose$ photons" step includes the kinematic acceptance cuts. The cross-section times branching ratio for the spin-0 sample is normalized to the MadGraph NLO prediction of 112~fb and the cross-section times branching ratio for the graviton corresponds to the Pythia8 prediction of 12~fb.

Effect of event selections on a NWA spin-0 and a spin-2 ($k/Mpl=0.01$) MC samples generated for m_X = 1 TeV and on the data. For the MC samples, the event yield is shown after applying event weights; for the data, the absolute yields are shown. The initial yields for data include a trigger preselection that is the OR of a list of single photon and diphoton triggers. The "2 $loose$ photons" step includes the kinematic acceptance cuts. The cross-section times branching ratio for the spin-0 sample is normalized to the MadGraph NLO prediction of 112~fb and the cross-section times branching ratio for the graviton corresponds to the Pythia8 prediction of 12~fb.

Parameterization for the CX and AX factors as function of mX for a scalar particle, as obtained from the narrow-width MC signal samples.

Parameterization for the CX and AX factors as function of mX for a scalar particle, as obtained from the narrow-width MC signal samples.

Parameterization for the $C_{X}\cdot A_{X}$ factor as function of $m_{G^*}$ for the RS graviton, as obtained from k/MPl = 0.05 MC signal samples.

Parameterization for the $C_{X}\cdot A_{X}$ factor as function of $m_{G^*}$ for the RS graviton, as obtained from k/MPl = 0.05 MC signal samples.

Parameterization of the Double Sided Crystal Ball function parameters describing the scalar mass resolution model as a function of m_{X} [GeV].

Parameterization of the Double Sided Crystal Ball function parameters describing the scalar mass resolution model as a function of m_{X} [GeV].

Parameterization of the Double Sided Crystal Ball function parameters describing the graviton mass resolution model as a function of m_{X} [GeV].

Parameterization of the Double Sided Crystal Ball function parameters describing the graviton mass resolution model as a function of m_{X} [GeV].

Distribution of the dimuon invariant mass for events passing the full selection.

Distribution of the dimuon invariant mass for events passing the full selection.

Distribution of the dimuon invariant mass for events passing the full selection.

Expected upper limits at 95% CL on the fiducial cross-section times branching ratio as a function of pole mass for the zero-width, 0.5%, 1.2%, 3%, 6% and 10% relative width signals for the combined dilepton channel.

Expected upper limits at 95% CL on the fiducial cross-section times branching ratio as a function of pole mass for the zero-width, 0.5%, 1.2%, 3%, 6% and 10% relative width signals for the combined dilepton channel.

Expected upper limits at 95% CL on the fiducial cross-section times branching ratio as a function of pole mass for the zero-width, 0.5%, 1.2%, 3%, 6% and 10% relative width signals for the combined dilepton channel.

Observed upper limits at 95% CL on the fiducial cross-section times branching ratio as a function of pole mass for the zero-width, 0.5%, 1.2%, 3%, 6% and 10% relative width signals for the combined dilepton channel.

Observed upper limits at 95% CL on the fiducial cross-section times branching ratio as a function of pole mass for the zero-width, 0.5%, 1.2%, 3%, 6% and 10% relative width signals for the combined dilepton channel.

Observed upper limits at 95% CL on the fiducial cross-section times branching ratio as a function of pole mass for the zero-width, 0.5%, 1.2%, 3%, 6% and 10% relative width signals for the combined dilepton channel.

Expected upper limits at 95% CL on the fiducial cross-section times branching ratio as a function of pole mass for the zero-width, 0.5%, 1.2%, 3%, 6% and 10% relative width signals for the dielectron channel.

Expected upper limits at 95% CL on the fiducial cross-section times branching ratio as a function of pole mass for the zero-width, 0.5%, 1.2%, 3%, 6% and 10% relative width signals for the dielectron channel.

Expected upper limits at 95% CL on the fiducial cross-section times branching ratio as a function of pole mass for the zero-width, 0.5%, 1.2%, 3%, 6% and 10% relative width signals for the dielectron channel.

Observed upper limits at 95% CL on the fiducial cross-section times branching ratio as a function of pole mass for the zero-width, 0.5%, 1.2%, 3%, 6% and 10% relative width signals for the dielectron channel.

Observed upper limits at 95% CL on the fiducial cross-section times branching ratio as a function of pole mass for the zero-width, 0.5%, 1.2%, 3%, 6% and 10% relative width signals for the dielectron channel.

Observed upper limits at 95% CL on the fiducial cross-section times branching ratio as a function of pole mass for the zero-width, 0.5%, 1.2%, 3%, 6% and 10% relative width signals for the dielectron channel.

Expected upper limits at 95% CL on the fiducial cross-section times branching ratio as a function of pole mass for the zero-width, 0.5%, 1.2%, 3%, 6% and 10% relative width signals for the dimuon channel.

Expected upper limits at 95% CL on the fiducial cross-section times branching ratio as a function of pole mass for the zero-width, 0.5%, 1.2%, 3%, 6% and 10% relative width signals for the dimuon channel.

Expected upper limits at 95% CL on the fiducial cross-section times branching ratio as a function of pole mass for the zero-width, 0.5%, 1.2%, 3%, 6% and 10% relative width signals for the dimuon channel.

Observed upper limits at 95% CL on the fiducial cross-section times branching ratio as a function of pole mass for the zero-width, 0.5%, 1.2%, 3%, 6% and 10% relative width signals for the dimuon channel.

Observed upper limits at 95% CL on the fiducial cross-section times branching ratio as a function of pole mass for the zero-width, 0.5%, 1.2%, 3%, 6% and 10% relative width signals for the dimuon channel.

Observed upper limits at 95% CL on the fiducial cross-section times branching ratio as a function of pole mass for the zero-width, 0.5%, 1.2%, 3%, 6% and 10% relative width signals for the dimuon channel.

Ratio of the observed limit to the Z'$_\mathrm{SSM}$ cross-section for the combination of the dielectron and dimuon channels. A number of previous ATLAS results at $\sqrt{s}$ = 7, 8, and 13 TeV are compared to the current search.

Ratio of the observed limit to the Z'$_\mathrm{SSM}$ cross-section for the combination of the dielectron and dimuon channels. A number of previous ATLAS results at $\sqrt{s}$ = 7, 8, and 13 TeV are compared to the current search.

Ratio of the observed limit to the Z'$_\mathrm{SSM}$ cross-section for the combination of the dielectron and dimuon channels. A number of previous ATLAS results at $\sqrt{s}$ = 7, 8, and 13 TeV are compared to the current search.

Observed 95% exclusion contours in the HVT parameter space $\{g_h,g_f\}$ with $g_f\equiv g_l=g_q$ for a resonance mass of 3 TeV for the dilepton channel. The area outside the curves is excluded.

Observed 95% exclusion contours in the HVT parameter space $\{g_h,g_f\}$ with $g_f\equiv g_l=g_q$ for a resonance mass of 3 TeV for the dilepton channel. The area outside the curves is excluded.

Observed 95% exclusion contours in the HVT parameter space $\{g_h,g_f\}$ with $g_f\equiv g_l=g_q$ for a resonance mass of 3 TeV for the dilepton channel. The area outside the curves is excluded.

Observed 95% exclusion contours in the HVT parameter space $\{g_h,g_f\}$ with $g_f\equiv g_l=g_q$ for a resonance mass of 4 TeV for the dilepton channel. The area outside the curves is excluded.

Observed 95% exclusion contours in the HVT parameter space $\{g_h,g_f\}$ with $g_f\equiv g_l=g_q$ for a resonance mass of 4 TeV for the dilepton channel. The area outside the curves is excluded.

Observed 95% exclusion contours in the HVT parameter space $\{g_h,g_f\}$ with $g_f\equiv g_l=g_q$ for a resonance mass of 4 TeV for the dilepton channel. The area outside the curves is excluded.

Observed 95% exclusion contours in the HVT parameter space $\{g_h,g_f\}$ with $g_f\equiv g_l=g_q$ for a resonance mass of 5 TeV for the dilepton channel. The area outside the curves is excluded.

Observed 95% exclusion contours in the HVT parameter space $\{g_h,g_f\}$ with $g_f\equiv g_l=g_q$ for a resonance mass of 5 TeV for the dilepton channel. The area outside the curves is excluded.

Observed 95% exclusion contours in the HVT parameter space $\{g_h,g_f\}$ with $g_f\equiv g_l=g_q$ for a resonance mass of 5 TeV for the dilepton channel. The area outside the curves is excluded.

Observed 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance mass of 3 TeV for the dilepton channel. The area outside the curves is excluded.

Observed 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance mass of 3 TeV for the dilepton channel. The area outside the curves is excluded.

Observed 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance mass of 3 TeV for the dilepton channel. The area outside the curves is excluded.

Observed 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance mass of 4 TeV for the dilepton channel. The area outside the curves is excluded.

Observed 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance mass of 4 TeV for the dilepton channel. The area outside the curves is excluded.

Observed 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance mass of 4 TeV for the dilepton channel. The area outside the curves is excluded.

Observed 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance mass of 5 TeV for the dilepton channel. The area outside the curves is excluded.

Observed 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance mass of 5 TeV for the dilepton channel. The area outside the curves is excluded.

Observed 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance mass of 5 TeV for the dilepton channel. The area outside the curves is excluded.

Expected 95% exclusion contours in the HVT parameter space $\{g_h,g_f\}$ with $g_f\equiv g_l=g_q$ for a resonance mass of 3 TeV for the dilepton channel. The area outside the curves is excluded.

Expected 95% exclusion contours in the HVT parameter space $\{g_h,g_f\}$ with $g_f\equiv g_l=g_q$ for a resonance mass of 3 TeV for the dilepton channel. The area outside the curves is excluded.

Expected 95% exclusion contours in the HVT parameter space $\{g_h,g_f\}$ with $g_f\equiv g_l=g_q$ for a resonance mass of 3 TeV for the dilepton channel. The area outside the curves is excluded.

Expected 95% exclusion contours in the HVT parameter space $\{g_h,g_f\}$ with $g_f\equiv g_l=g_q$ for a resonance mass of 4 TeV for the dilepton channel. The area outside the curves is excluded.

Expected 95% exclusion contours in the HVT parameter space $\{g_h,g_f\}$ with $g_f\equiv g_l=g_q$ for a resonance mass of 4 TeV for the dilepton channel. The area outside the curves is excluded.

Expected 95% exclusion contours in the HVT parameter space $\{g_h,g_f\}$ with $g_f\equiv g_l=g_q$ for a resonance mass of 4 TeV for the dilepton channel. The area outside the curves is excluded.

Expected 95% exclusion contours in the HVT parameter space $\{g_h,g_f\}$ with $g_f\equiv g_l=g_q$ for a resonance mass of 5 TeV for the dilepton channel. The area outside the curves is excluded.

Expected 95% exclusion contours in the HVT parameter space $\{g_h,g_f\}$ with $g_f\equiv g_l=g_q$ for a resonance mass of 5 TeV for the dilepton channel. The area outside the curves is excluded.

Expected 95% exclusion contours in the HVT parameter space $\{g_h,g_f\}$ with $g_f\equiv g_l=g_q$ for a resonance mass of 5 TeV for the dilepton channel. The area outside the curves is excluded.

Expected 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance masses of 3 TeV for the dilepton channel. The area outside the curves is excluded.

Expected 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance masses of 3 TeV for the dilepton channel. The area outside the curves is excluded.

Expected 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance masses of 3 TeV for the dilepton channel. The area outside the curves is excluded.

Expected 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance masses of 4 TeV for the dilepton channel. The area outside the curves is excluded.

Expected 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance masses of 4 TeV for the dilepton channel. The area outside the curves is excluded.

Expected 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance masses of 4 TeV for the dilepton channel. The area outside the curves is excluded.

Expected 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance masses of 5 TeV for the dilepton channel. The area outside the curves is excluded.

Expected 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance masses of 5 TeV for the dilepton channel. The area outside the curves is excluded.

Expected 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance masses of 5 TeV for the dilepton channel. The area outside the curves is excluded.

Dielectron and dimuon selection efficiency as a function of pole mass for spin-0, spin-1 and spin-2 resonances. Drell-Yan MC samples are used for the spin-1 efficiencies and correspond to the zero-width signal hypothesis. Spin-0 (spin-2) efficiencies are obtained from dedicated MC samples with relative widths in the range of 0-20% (1-13%) and are averaged over all available width assumptions.

Dielectron and dimuon selection efficiency as a function of pole mass for spin-0, spin-1 and spin-2 resonances. Drell-Yan MC samples are used for the spin-1 efficiencies and correspond to the zero-width signal hypothesis. Spin-0 (spin-2) efficiencies are obtained from dedicated MC samples with relative widths in the range of 0-20% (1-13%) and are averaged over all available width assumptions.

Dielectron and dimuon selection efficiency as a function of pole mass for spin-0, spin-1 and spin-2 resonances. Drell-Yan MC samples are used for the spin-1 efficiencies and correspond to the zero-width signal hypothesis. Spin-0 (spin-2) efficiencies are obtained from dedicated MC samples with relative widths in the range of 0-20% (1-13%) and are averaged over all available width assumptions.

Description of the $m_{\ell\ell}^{\mathrm{true}}$-dependence for the seven relative mass resolution parameters in the dielectron channel.

Description of the $m_{\ell\ell}^{\mathrm{true}}$-dependence for the seven relative mass resolution parameters in the dielectron channel.

Description of the $m_{\ell\ell}^{\mathrm{true}}$-dependence for the seven relative mass resolution parameters in the dielectron channel.

Description of the $m_{\ell\ell}^{\mathrm{true}}$-dependence for the seven relative mass resolution parameters in the dimuon channel.

Description of the $m_{\ell\ell}^{\mathrm{true}}$-dependence for the seven relative mass resolution parameters in the dimuon channel.

Description of the $m_{\ell\ell}^{\mathrm{true}}$-dependence for the seven relative mass resolution parameters in the dimuon channel.