Reconstructed mass of $\rho^{0}$ meson in 40-60$\%$ central Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76~{\rm TeV}$.

Reconstructed mass of $\rho^{0}$ meson in 60-80$\%$ central Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76~{\rm TeV}$.

Yield of $\rho^{0}$ meson normalized to the number of inelastic pp collisions at $\sqrt{s}=2.76~{\rm TeV}$.

Yield of $\rho^{0}$ meson in 0-20$\%$ central Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76~{\rm TeV}$.

Yield of $\rho^{0}$ meson in 20-40$\%$ central Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76~{\rm TeV}$.

Yield of $\rho^{0}$ meson in 40-60$\%$ central Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76~{\rm TeV}$.

Yield of $\rho^{0}$ meson in 60-80$\%$ central Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76~{\rm TeV}$.

Ratio of integrated yields $2\rho^{0}/(\pi^{+}+\pi^{-})$ as a function of $(dN_{ch}/d\eta)^{1/3}$ in pp and 0-20$\%$, 20-40$\%$, 40-60$\%$, 60-80$\%$ central Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76~{\rm TeV}$.

Mean transverse momentum of $\rho^{0}$ meson as a function of $(dN_{ch}/d\eta)^{1/3}$ in pp and 0-20$\%$, 20-40$\%$, 40-60$\%$, 60-80$\%$ central Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76~{\rm TeV}$.

Ratio $2\rho^{0}/(\pi^{+}+\pi^{-})$ as a function of $p_{T}$ in pp collisions at $\sqrt{s}=2.76~{\rm TeV}$.

Ratio $2\rho^{0}/(\pi^{+}+\pi^{-})$ as a function of $p_{T}$ in 0-20$\%$ central Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76~{\rm TeV}$.

Ratio $2\rho^{0}/(\pi^{+}+\pi^{-})$ as a function of $p_{T}$ in 60-80$\%$ central Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76~{\rm TeV}$.

$R_{AA}$ as a function of $p_{T}$ in 0-20$\%$ central Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76~{\rm TeV}$.

$R_{AA}$ as a function of $p_{T}$ in 20-40$\%$ central Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76~{\rm TeV}$.

$R_{AA}$ as a function of $p_{T}$ in 40-60$\%$ central Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76~{\rm TeV}$.

$R_{AA}$ as a function of $p_{T}$ in 60-80$\%$ central Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76~{\rm TeV}$.

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 $m_{\textrm{med}}>2m_{\chi}$.