Azimuthal distribution of charged particles in Pb-Pb collisions at 2.76 TeV

We analyze the azimuthal distributions of charged particles produced in 2.76 TeV Pb-Pb collisions from ATLAS experimental group in eight different centralities by using the multi-source thermal model. The modeling results are compared with the results from Fourier series forms with n = 2, 4, 6 and n = 2. Meanwhile, the anisotropy ratios and the relative expansion rates of scattering source in transverse momentum space are calculated applying the transverse structural parameters of multi-source thermal model, and the modeling results are compared with the associated fourier coefficients. The anisotropy ratios and the relative expansion rates are less than the corresponding fourier coefficients in transverse momentum space in different center intervals. Elliptical anisotropy is main component in azimuthal distribution. Other anisotropies have different contributions in different centralities. and these contributions cannot be neglected. (authors)