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

Submission Date: 
Article Information
Submission Form
2.76 TeV
Abstract Plain Text: 

The transverse momentum ($p_{T}$) spectra of $K^{*0}$ and $\phi$ have been measured up to $p_{T}$ ~ 20 GeV/c in pp and Pb-Pb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV using the ALICE detector at the Large Hadron Collider. The measurements are done for different collision centrality intervals at mid-rapidity (|y|<0.5). The invariant cross-section of these mesons in pp collisions are compared to the PYTHIA and PHOJET model calculations. The Nuclear modification factor $R_{AA}$ ($R_{CP}$) of $K^{*0}$ and $\phi$ are measured and  compared to that of charged hadrons, $\pi$, K and p ($\Lambda$ and $K_{S}^{0}$) in various collision centrality intervals. The production of $K^{*0}$ and $\phi$ at are strongly suppressed in most central collisions with respect to pp collisions. For $p_{T} > $ 9 GeV/c, the $R_{AA}$  of $K^{*0}$ and $\phi$ is found to be similar with that of $\pi$, K and p supporting the flavor independence of partonic energy loss in the medium. The additional suppression of $K^{*0}$ $R_{AA}$ with respect to charged hadrons (and $\phi$) for $p_{T} < $ 2 GeV/c may be reflecting the effect of hadronic re-scattering. The particle ratios of $K^{*0}$ and $\phi$  relative to pions (and kaons) have been obtained in pp and central Pb-Pb collisions. The $\phi/\pi$ ratio in 0-5$\%$ central Pb-Pb collisions shows an enhancement for $p_{T}$ ~ 3 GeV/c.