Paper detail

A study of the anisotropy associated with dipole asymmetry in heavy ion collisions

The anisotropy associated with the initial dipole asymmetry in heavy ion collisions is studied via the two-particle relative azimuthal azimuthal angle (Δϕ=ϕ^a-ϕ^b) correlations, within a multi-phase transport model. For a broad selection of centrality, transverse momenta (pT^{a,b}) and pseudorapidity (η^{a,b}), a fitting method is used to decompose the anisotropy into a rapidity-even component, characterized by the Fourier coefficient v1, and a global momentum conservation component. The extracted v1 values are negative for pT<=0.7-0.9 GeV, reach a maximum at 2-3 GeV, and decreases at higher pT. The v1 values vary weakly with ηand centrality, but increases with collision energy and parton cross-section. The extracted global momentum conservation component is found to depend on Δη= η^a-η^b for Δη<3.