Impact of the initial size of spatial fluctuations on the collective flow in Pb-Pb collisions at root S-NN=2.76 TeV

摘要

The Parton-Hadron-String-Dynamics transport model is used to study the influence of the initial size of spatial fluctuations of the interacting system on flow observables in Pb-Pb collisions at root S-NN = 2.76 TeV for different centralities. While the flow coefficients nu(2), nu(3), nu(4) and nu(5) are reasonably described in comparison to the data from the ALICE Collaboration for different centralities within the default setting, no essential sensitivity is found with respect to the initial size of spatial fluctuations even for very central collisions where the flow coefficients are dominated by the size of initial state fluctuations. We attribute this lack of sensitivity partly to the low interaction rate of the degrees-offreedom in this very early phase of order similar to 0.3 fm c(-1) which is also in common with the weakly interacting color glass condensate or glasma approach. Moreover, since the event shape in the transverse plane is approximately the same for different size of spatial fluctuations very similar eccentricities c(n) are transformed to roughly the same flow coefficients nu(n) in momentum space.