Transverse momentum dependent decorrelation in Pb-Pb collisions at LHC

Based on A Multi-Phase Transport (AMPT) model simulations, the transverse momentum dependent decorrelation has been studied in Pb-Pb collisions at root s(NN) = 2.76 and 5.02 TeV, respectively. It has been found that the mix-order factorization ratio r(m, n) value deviates significantly from unity in noncentral collisions. Such effect becomes stronger with an increase in the p(T) difference p(T)(a) -p(T)(b). These decorrelations are not only between the same order harmonic but also between the different order harmonic, which as a result of the initial fluctuations appear between the different phase spaces. It has also been found that the correlations involving higher powers of the flow vector yield stronger decorrelation, r(m vertical bar n;3) < r(m)(vertical bar n;2) < r(m)(vertical bar)(n;1) (m = 2, 3; n = 2, 3,4, 5), except for the weighted factorization ratio r(3)(vertical bar)(4;k). The breaking phenomenon of these factorization ratios indicated that, it provides a possible observation for studying the initial fluctuation properties of heavy-ion collisions.