Λ and K0^0S_S production in Pb-Pb and pp collisions with ALICE at the LHC

In this work, the transverse momentum spectra of Λ and K$^0$$_S$ measured with the ALICE experiment at the LHC are discussed. Measurements are presented for colliding systems of protons, at centre of mass energies 2.76 TeV and 7 TeV, and for lead ions at a centre of mass energy of 2.76 TeV per nucleon. The spectra are discussed within a theoretical framework of a thermally equilibrated, hydrodynamically evolving system, which serves to explain the shape of the spectra for p$_T$ 6 GeV/c jet quenching is evident, but no evidence of particle species dependance in jet quenching is observed. The Λ/K$^0$$_S$ ratio shows an enhancement for 2 < p$_T$ < 6 GeV/c, peaking at 1.5 for the 5% most central Pb–Pb collisions compared to 0.6 for pp. This is discussed in terms of a coalescence model. It cannot be explained purely by enhanced baryon production, but must also involve a redistribution of particles within p$_T$. This supports the hydrodynamical picture of hadron production. A brief comparison to the results presently available in p–Pb collisions at the LHC is also given

KS0K^0_S & Λ\Lambda Production in ALICE

The production of Λ and K0S hadrons at the LHC can be measured through the reconstruction of their weak decay topologies via decay channels with only charged particles in the final state. The tracking and particle identification capabilities of the ALICE detector allow us to measure the spectra of these particles over a wide transverse momentum range (0.4 < pT < 12 GeV/c), and to precisely determine the behaviour of the baryon-to-meson ratio Λ/K0S.Transverse momentum spectra and production yields at mid-rapidity (|y| < 0.5) for Λ and K0S are presented for = 2.76 TeV Pb-Pb collisions as a function of centrality. The evolution of the Λ/K0S ratio is discussed, in comparison with corresponding results in pp collisions at the LHC and in = 200 GeV Au-Au collisions at RHIC. Comparisons to theoretical models will also be outlined