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

The production of the $\rho(770)^{0}$ meson has been measured at mid-rapidity (|y| < 0.5) in pp and centrality differential Pb-Pb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV with the ALICE detector at the Large Hadron Collider. The particles have been reconstructed in the $\rho(770)^{0}\rightarrow \pi^{+}\pi^{-}$ 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 $2\rho(770)^{0}/(\pi^{+}+\pi^{-})$ is observed. The ratio decreases by ~40% from pp to central Pb-Pb collisions. A study of the $p_{T}$-differential $2\rho(770)^{0}/(\pi^{+}+\pi^{-})$ 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 $K^{*}(892)^{0}/K$ ratio and is consistent with EPOS3 predictions that may imply that rescattering in the hadronic phase is a dominant mechanism for the observed suppression.