Investigation of possible hadronic flow in v √sNN=5.02 TeV p-Pb collisions

Using the ultrarelativistic quantum molecular dynamics (UrQMD) model, we investigate azimuthal correlations in p-Pb collisions at root s(NN) = 5.02 TeV. Comparison with the experimental data shows that UrQMD cannot reproduce the multiplicity dependence of two- and four-particle cumulants, especially the transition from positive to negative values of c(2){4} in high-multiplicity events, which has been taken as experimental evidence of collectivity in p-Pb collisions. Meanwhile, UrQMD cannot describe the differential elliptic flow v(2)(pT) of all charged hadrons at various multiplicity classes. These discrepancies show that the simulated hadronic p-Pb systems cannot generate enough collective flow as observed in experiment, the associated hadron emissions are largely influenced by nonflow effects. However, the characteristic v(2)(pT) mass ordering of pions, kaons, and protons is observed in UrQMD, which is the consequence of hadronic interactions and not necessarily associated with strong fluid-like expansions.