K\(^{*}(892)^{0}\) and \(\phi(1020)\) meson production at high transverse momentum in pp and Pb-Pb collisions at \(\sqrt{s_\mathrm{NN}}\) = 2.76 TeV

Abstract

The production of K\).{*}(892)^{0}\) and \(\phi(1020)\) mesons in proton-proton (pp) and lead-lead (Pb-Pb) collisions at \(\sqrt{s_\mathrm{NN}} =\) 2.76 TeV has been analyzed using a high luminosity data sample accumulated in 2011 with the ALICE detector at the Large Hadron Collider (LHC). Transverse momentum \(p_{\mathrm{T}}\) spectra have been measured for K\).{*}(892)^{0}\) and \(\phi(1020)\) mesons via their hadronic decay channels for \(p_{\mathrm{T}}\) up to 20 GeV/\).\). The measurements in pp collisions have been compared to model calculations and used to determine the nuclear modification factor and particle ratios. The K\).{*}(892)^{0}\).K ratio exhibits significant reduction from pp to central Pb-Pb collisions, consistent with the suppression of the K\).{*}(892)^{0}\) yield at low \(p_{\mathrm{T}}\) due to rescattering of its decay products in the hadronic phase. In central Pb-Pb collisions the \(p_{\mathrm{T}}\) dependent \(\phi(1020)/\pi\) and K\).{*}(892)^{0}\).\).pi\) ratios show an enhancement over pp collisions for \(p_{\mathrm{T}}\) \(\sim\). GeV/\).\). consistent with previous observations of strong radial flow. At high \(p_{\mathrm{T}}\). particle ratios in Pb-Pb collisions are similar to those measured in pp collisions. In central Pb-Pb collisions, the production of K\).{*}(892)^{0}\) and \(\phi(1020)\) mesons is suppressed for \(p_{\mathrm{T}}> 8\) GeV/\).\). This suppression is similar to that of charged pions, kaons and protons, indicating that the suppression does not depend on particle mass or flavor in the light quark sector.