p(T)-dependent particle number fluctuations from principal-component analyses in hydrodynamic simulations of heavy-ion collisions

摘要

We carry out a principal component analysis of fluctuations in a hydrodynamic simulation of heavy-ion collisions, and compare with experimental data from the CMS Collaboration. The principal components of anisotropic flow reproduce the trends seen in data, but multiplicity fluctuations show a difference in transverse momentum dependence. We construct an analytical toy model and verify that hydrodynamic simulations agree with its predictions. The difference in the momentum trend is likely due to larger fluctuations in transverse momentum of hydrodynamic models than seen experimentally.