Production of the $\rho$(770)${}^0$ meson in pp and Pb-Pb collisions at $\sqrt{s_{\mathrm{N}\mathrm{N}}}$ = 2.76 TeV

The production of the $\rho$(770)${}^0$ meson has been measured at mid-rapidity $(\mathrm{\mid }y\mathrm{\mid }<0.5)$ in pp and centrality differential Pb-Pb collisions at $\sqrt{s_{\mathrm{N}\mathrm{N}}}$ = 2.76 TeV with the ALICE detector at the Large Hadron Collider. The particles have been reconstructed in the $\rho$(770)$\to {\pi }^{+}{\pi }^{-}$ decay channel in the transverse momentum ($p_T$) range $0.5-11$ GeV/$c$. A centrality dependent suppression of the ratio of the integrated yields $2\rho$(770)${}^0\mathrm{/}({\pi }^{+}+{\pi }^{-})$ is observed. The ratio decreases by $\sim 40\mathrm{\%}$ from pp to central Pb-Pb collisions. A study of the $p_T$-differential $2\rho$(770)${}^0\mathrm{/}({\pi }^{+}+{\pi }^{-})$ ratio reveals that the suppression occurs at low transverse momenta, $p_T<2$ GeV/$c$. At higher momentum, particle ratios measured in heavy-ion and pp collisions are consistent. The observed suppression is very similar to that previously measured for the $K^{\ast }$(892)${}^0\mathrm{/}K$ ratio and is consistent with EPOS3 predictions that may imply that rescattering in the hadronic phase is a dominant mechanism for the observed suppression.