K0sK0s correlations in 7 TeV proton+proton collisions from the ALICE experiment at the LHC

May 23, 2011, 6:10 PM
Rotonde de l'Europe (Imperial Palace)

Rotonde de l'Europe

Imperial Palace

Parallel Correlations and fluctuations Correlations and fluctuations


Prof. Thomas Humanic (Relativistic Heavy Ion Group, Department of Physics - Ohio State U.)


Identical neutral kaon pair correlations are measured in 7 TeV proton+proton collisions in the ALICE experiment. Neutral kaons are identified from their decay into π+π- pairs. K0sK0s correlation functions are formed in 4 multiplicity x 4 kT bins. The kaon source parameters Rinv and λ are extracted from these correlation functions by fitting a Gaussian*PYTHIA model to them, the Gaussian describing the Bose effect and PYTHIA accounting for the non-flat baseline found in proton+proton collisions. PYTHIA with the Perugia-0 tune is seen to describe well the dependence of the baseline shape of the K0sK0s correlation function on multiplicity-kT bin in the Qinv fitting range used of 0-1 GeV. Corrections to source parameters from the Lednicky model for the a0/f0 resonance are made and found to be large. K0sK0s correlations show a systematic increase in Rinv for increasing multiplicity bin and decreasing Rinv for increasing kT bin as seen in ππ correlations in the proton+proton system, as well as seen in heavy-ion collisions. Also, K0sK0s correlations are observed to more or less “smoothly” extend this ππ Rinv behavior for the proton+proton system to ~3 times higher kT than the kT range measured in ππ correlations.

Primary author

Prof. Thomas Humanic (Relativistic Heavy Ion Group, Department of Physics - Ohio State U.)

Presentation materials