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Compact Muon Solenoid
LHC, CERN

CMS-PAS-HIN-15-006
Multiplicity and rapidity dependence of strange hadron spectra in pp, pPb, and PbPb collisions at LHC energies
Abstract: Measurements of strange hadron ($\mathrm{K}^{0}_{s}$, $\Lambda^{+}+\Lambda^{-}$ and $\Xi^{+}+\Xi^{-}$) transverse momentum ($p_{\mathrm{T}}$) spectra in pp, pPb and PbPb collisions are presented 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 $\sqrt{s} =$ 7 TeV, pPb collisions at $\sqrt{s_{NN}} =$ 5.02 TeV and PbPb collisions at $\sqrt{s_{NN}} =$ 2.76 TeV. The average transverse kinetic energy ($KE^{}_{\mathrm{T}}$) is found to increase with event multiplicity, with a faster rate for heavier particle species. At similar multiplicities, the separation in the $KE^{}_{\mathrm{T}}$ between different particle species is observed to be larger for pp and pPb systems than PbPb system. In pPb collisions, the average $KE^{}_{\mathrm{T}}$ 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. The data are compared to models motivated by hydrodynamics.
CMS Publications
Compact Muon Solenoid
LHC, CERN