Distribution of missing transverse momentum in the data and for the background in the PhJetCR. The total background expectation is normali zed to the post-fit result. The errors include both statistical and systematic uncertainties determined by a bin-by-bin fit.

Distribution of missing transverse momentum in the signal region for data and for the background predicted from the fit in the CRs. Overflows are included in the final bin. The errors include both statistical and systematic components. The expected yield of events from the simplified model with $m_\chi$ = 150 GeV and $m_{med}$ = 500 GeV is also shown.

Distribution of photon transverse momentum in the signal region for data and for the background predicted from the fit in the CRs. Overflows are included in the final bin. The errors include both statistical and systematic components. The expected yield of events from the simplified model with $m_\chi$ = 150 GeV and $m_{med}$ = 500 GeV is also shown.

The observed and 95% CL exclusion limit for a simplified model of dark matter production involving an axial-vector operator, Dirac DM and couplings $g_q$ = 0.25 and $g_\chi$ = 1 as a function of the dark matter mass $m_\chi$ and the axial-mediator mass $m_{med}$.

The observed 90% CL exclusion limit on the DM-proton scattering cross section in a simplifed model of dark matter production involving an axial-vector operator, Dirac DM and couplings $g_q$ = 0.25 and $g_\chi$ = 1 as a function of the dark matter mass $m_\chi$.

The observed 95% CL lower limits on $M_\ast$ for a dimension-7 operator EFT model with a contact interaction of type $\gamma\gamma\chi\chi$ as a function of dark matter mass $m_\chi$.

The observed 95% CL lower limits on the mass scale $M_D$ in the ADD models of large extra dimensions, for several values of the number of extra dimensions.

The expected 95% CL exclusion contour (-1$\sigma$) for a simplified model of dark-matter production involving an axial-vector operator, Dirac DM and couplings $g_{q}$ = 0.25, $g_{\chi}$ = 1 and $g_{l}$ = 0 as a function of the dark-matter mass $m_{\chi}$ and the mediator mass $m_{\mathrm{med}}$. The plane under the limit curve is excluded.

The expected 95% CL exclusion contour for a simplified model of dark-matter production involving an axial-vector operator, Dirac DM and couplings $g_{q}$ = 0.25, $g_{\chi}$ = 1 and $g_{l}$ = 0 as a function of the dark-matter mass $m_{\chi}$ and the mediator mass $m_{\mathrm{med}}$. The plane under the limit curve is excluded.

The observed 95% CL exclusion contour for a simplified model of dark-matter production involving an axial-vector operator, Dirac DM and couplings $g_{q}$ = 0.1, $g_{\chi}$ = 1 and $g_{l}$ = 0.1 as a function of the dark-matter mass $m_{\chi}$ and the mediator mass $m_{\mathrm{med}}$. The plane under the limit curve is excluded.

The expected 95% CL exclusion contour (+1$\sigma$) for a simplified model of dark-matter production involving an axial-vector operator, Dirac DM and couplings $g_{q}$ = 0.1, $g_{\chi}$ = 1 and $g_{l}$ = 0.1 as a function of the dark-matter mass $m_{\chi}$ and the mediator mass $m_{\mathrm{med}}$. The plane under the limit curve is excluded.

The expected 95% CL exclusion contour (-1$\sigma$) for a simplified model of dark-matter production involving an axial-vector operator, Dirac DM and couplings $g_{q}$ = 0.1, $g_{\chi}$ = 1 and $g_{l}$ = 0.1 as a function of the dark-matter mass $m_{\chi}$ and the mediator mass $m_{\mathrm{med}}$. The plane under the limit curve is excluded.

The expected 95% CL exclusion contour for a simplified model of dark-matter production involving an axial-vector operator, Dirac DM and couplings $g_{q}$ = 0.1, $g_{\chi}$ = 1 and $g_{l}$ = 0.1 as a function of the dark-matter mass $m_{\chi}$ and the mediator mass $m_{\mathrm{med}}$. The plane under the limit curve is excluded.

The observed 95% CL exclusion contour for a simplified model of dark-matter production involving a vector operator with couplings $g_{q}$ = 0.25, $g_{\chi}$ =1 and $g_{l}$ = 0 as a function of the dark-matter mass $m_{\chi}$ and the mediator mass $m_{\mathrm{med}}$. The plane under the limit curve is excluded.

The expected 95% CL exclusion contour ($+1\sigma$) for a simplified model of dark-matter production involving a vector operator with couplings $g_{q}$ = 0.25, $g_{\chi}$ =1 and $g_{l}$ = 0 as a function of the dark-matter mass $m_{\chi}$ and the mediator mass $m_{\mathrm{med}}$. The plane under the limit curve is excluded.

The expected 95% CL exclusion contour ($-1\sigma$) for a simplified model of dark-matter production involving a vector operator with couplings $g_{q}$ = 0.25, $g_{\chi}$ =1 and $g_{l}$ = 0 as a function of the dark-matter mass $m_{\chi}$ and the mediator mass $m_{\mathrm{med}}$. The plane under the limit curve is excluded.

The expected 95% CL exclusion contour for a simplified model of dark-matter production involving a vector operator with couplings $g_{q}$ = 0.25, $g_{\chi}$ =1 and $g_{l}$ = 0 as a function of the dark-matter mass $m_{\chi}$ and the mediator mass $m_{\mathrm{med}}$. The plane under the limit curve is excluded.

The observed 95% CL exclusion contour for a simplified model of dark-matter production involving for a vector operator with couplings $g_{q}$ = 0.1, $g_{\chi}$ = 1 and $g_{l}$ = 0.01 as a function of the dark-matter mass $m_{\chi}$ and the mediator mass $m_{\mathrm{med}}$. The plane under the limit curve is excluded.

The expected 95% CL exclusion contour ($+1\sigma$) for a simplified model of dark-matter production involving for a vector operator with couplings $g_{q}$ = 0.1, $g_{\chi}$ = 1 and $g_{l}$ = 0.01 as a function of the dark-matter mass $m_{\chi}$ and the mediator mass $m_{\mathrm{med}}$. The plane under the limit curve is excluded.

The expected 95% CL exclusion contour ($-1\sigma$) for a simplified model of dark-matter production involving for a vector operator with couplings $g_{q}$ = 0.1, $g_{\chi}$ = 1 and $g_{l}$ = 0.01 as a function of the dark-matter mass $m_{\chi}$ and the mediator mass $m_{\mathrm{med}}$. The plane under the limit curve is excluded.

The expected 95% CL exclusion contour for a simplified model of dark-matter production involving for a vector operator with couplings $g_{q}$ = 0.1, $g_{\chi}$ = 1 and $g_{l}$ = 0.01 as a function of the dark-matter mass $m_{\chi}$ and the mediator mass $m_{\mathrm{med}}$. The plane under the limit curve is excluded.

The 90% CL exclusion limit on the $\chi$-proton scattering cross section in a simplifed model of dark-matter production involving an axial-vector operator, Dirac DM and couplings $g_{q}$ = 0.25, $g_{\chi}$ = 1 and $g_{l}$ = 0 as a function of the dark-matter mass $m_{\chi}$.

The 90% CL exclusion limit on the $\chi$-nucleon scattering cross section in a simplifed model of dark-matter production involving a vector operator, Dirac DM and couplings $g_{q}$ = 0.25, $g_{\chi}$ = 1 and $g_{l}$ = 0 as a function of the dark-matter mass $m_{\chi}$.

The observed and expected 95% CL limits on M* for a dimension-7 operator EFT model with a contact interaction of type $\gamma\gamma\chi\chi$ as a function of dark-matter mass $m_{\chi}$.

The observed and expected limit at 95% CL on the production cross section of a $Z\gamma$ resonance as a function of its mass.

The observed 95% CL upper limits on signal strength $\mu$, the ratio of the experimental limit to the predicted signal cross section, for a simplified model of dark matter production involving an axial-vector operator, Dirac DM and couplings $g_{q}$ = 0.25 and $g_{\chi}$ = 1 as a function of the DM and the mediator particle masses. The bound on $\mu$ only applies for choices of couplings that yield the same kinematic distributions as the benchmark model.

Acceptance, in %, for a simplified model of dark matter production involving an axial-vector operator, Dirac DM and couplings $g_{q}$= 0.25 and $g_{\chi}$ = 1 for various $m_{\chi}$ and $m_{\textrm{med}}$ values. It is constant as a function of $m_{\chi}$ for a fixed $m_{\textrm{med}}$ in the region $m_{\textrm{med}}>2m_{\chi}$.

Fiducial reconstruction efficiencies in the three inclusive signal regions for a simplified model of dark matter production involving an axial-vector operator, Dirac DM and couplings $g_{q}$= 0.25 and $g_{\chi}$ = 1 for various $m_{\chi}$ and $m_{\textrm{med}}$ values. It is constant as a function of $m_{\chi}$ for a fixed $m_{\textrm{med}}$ in the region $m_{\textrm{med}}>2m_{\chi}$.