Strange particle production in proton-proton collisions at √(s)=0.9 TeV with ALICE at the LHC

The production of mesons containing strange quarks (K0S, φ) and both singly and doubly strange baryons (Λ, anti Λ, and Ξ-+ anti Ξ+) are measured at mid-rapidity in pp collisions at √(s) = 0.9 TeV with the ALICE experiment at the LHC. The results are obtained from the analysis of about 250 k minimum bias events recorded in 2009. Measurements of yields (dN/dy) and transverse momentum spectra at mid-rapidity for inelastic pp collisions are presented. For mesons, we report yields (left angle dN/dy right angle) of 0.184±0.002(stat.)±0.006(syst.) for K0S and 0.021±0.004(stat.)±0.003(syst.) for φ. For baryons, we find left angle dN/dy right angle =0.048±0.001(stat.)±0.004(syst.) for Λ, 0.047±0.002(stat.)±0.005(syst.) for anti Λ and 0.0101±0.0020(stat.)±0.0009(syst.) for Ξ+ anti Ξ+. The results are also compared with predictions for identified particle spectra from QCD-inspired models and provide a baseline for comparisons with both future pp measurements at higher energies and heavy-ion collisions. (orig.)