Measurements of [formula omitted], [formula omitted], and Ξ+ + Ξ− production in pp, pPb, and PbPb collisions with CMS

Abstract

We present measurements of strange hadron (Ks0, Λ+Λ‾, and Ξ++Ξ−) transverse momentum (pT) spectra in pp, pPb, and PbPb collisions over a wide range in charge-particle multiplicity and particle rapidity. The data were taken with the CMS detector at the LHC for pp collisions at s=7 TeV, pPb collisions at sNN=5.02 TeV, and PbPb collisions at sNN=2.76 TeV. We find the average transverse kinetic energy (KET) increases with event multiplicity, with a faster rate for heavier particle species. At similar multiplicities, we observe the separation in the 〈KET〉, which is defined as 〈KET〉=〈mT〉−m, where mT=m2+pT2, between different particle species is larger for pp and pPb systems than PbPb system. In pPb collisions, 〈KET〉 is found to be larger in the Pb-going direction than in the p-going direction. This trend of asymmetry becomes more evident for heavier particle species as event multiplicity increases. We also compare the data to models motivated by hydrodynamics.