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, phi) and both singly and doubly strange baryons (Lambda, Anti-Lambda, and Xi+Anti-Xi) are measured at central rapidity in pp collisions at $\sqrt{s}$ = 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 central rapidities for inelastic pp collisions are presented. For mesons, we report yields () of $0.184 \pm 0.002 stat. \pm 0.006 syst.$ for K0s and $0.021 \pm 0.004 stat. \pm 0.003 syst.$ for phi. For baryons, we find = 0.048 \pm 0.001 stat. \pm 0.004 syst.$ for $Lambda$, $0.047 \pm 0.002 stat. \pm 0.005 syst.$ for Anti-Lambda and $0.0101 \pm 0.0020 stat. \pm 0.0009 syst.$ for Xi+Anti-Xi. 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.