Pion, kaon, and proton femtoscopy in Pb--Pb collisions at $\sqrt{s_{\rm NN}}$=2.76 TeV modeled in 3+1D hydrodynamics

Abstract: Femtoscopy is providing information on system size and its dynamics in heavy-ion collisions. At ultra-relativistic energies, such as those obtained at the LHC, significant production of pions, kaons and protons enables femtoscopic measurements for these particles. In particular the dependence of system size on pair momentum and particle type is interpreted as evidence for strong collective flow. Such phenomena are naturally modeled by hydrodynamics. We present calculations within the 3+1D hydrodynamic model coupled to statistical hadronization code THERMINATOR 2, corresponding to Pb--Pb collisions at $\sqrt{s_{\rm NN}}=$2.76 TeV. We obtain femtoscopic radii for pions, kaons, and protons, as a function of pair transverse momentum and collision centrality. We find that an approximate universal scaling of radii with pair transverse mass and final state event multiplicity is observed, and discuss the consequences for the interpretation of experimental measurements.