Searches for transverse momentum dependent flow vector fluctuations in Pb–Pb and p–Pb collisions at the LHC

Abstract

The measurement of azimuthal correlations of charged particles is presented forPb–Pbcollisionsat√sNN =2.76TeVandp–Pbcollisionsat√sNN =5.02TeVwiththe ALICE detector at the CERN Large Hadron Collider. These correlations are measured for the second, third and fourth order flow vector in the pseudorapidity region |η| < 0.8 as a function of centrality and transverse momentum pT using two observables, to search for evidence of pT-dependent flow vector fluctuations. For Pb–Pb collisions at 2.76TeV, the measurements indicate that pT-dependent fluctuations are only present for the second order flow vector. Similar results have been found for p–Pb collisions at 5.02TeV. These measurements are compared to hydrodynamic model calculations with event-by-event ge- ometry fluctuations in the initial state to constrain the initial conditions and transport properties of the matter created in Pb–Pb and p–Pb collisions.