Strange particle production in proton–proton collisions at s=09 with ALICE at the LHC The ALICE Collaboration

The production of mesons containing strange quarks (, φ ) and both singly and doubly strange baryons (, , and ) are measured at mid-rapidity in pp collisions at  = 0.9  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 (d N /d y ) and transverse momentum spectra at mid-rapidity for inelastic pp collisions are presented. For mesons, we report yields (〈d N /d y 〉) of 0.184±0.002( stat .)±0.006( syst .) for and 0.021±0.004( stat .)±0.003( syst .) for  φ . For baryons, we find 〈d N /d y 〉=0.048±0.001( stat .)±0.004( syst .) for , 0.047±0.002( stat .)±0.005( syst .) for and 0.0101±0.0020( stat .)±0.0009( syst .) for . 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.