Anisotropic flow plays a crucial role in establishing the equation of state of the Quark Gluon Plasma. The results at RHIC and LHC have demonstrated that the matter created in heavy-ion collisions behaves as a nearly perfect fluid reflected in the low value of the shear viscosity over entropy density ratio ($\eta/s$). The higher flow harmonics are particularly sensitive to the value of $\eta/s$ in hydrodynamic calculations. In this analysis, we present the first ALICE results on the $p_{ \mathrm{ T}}$ differential $v_{ 2}$, $v_{ 3}$ and $v_{ 4}$ for $\pi^{ \pm}$, $\mathrm{ K}^{ \pm}$, p($\bar p$) from the high statistics 2011 heavy-ion run. We investigate how these $v_{ n}$ coefficients evolve with particle mass and centrality for the 0--1\% and 20--30\% centrality ranges. These new measurements aim at differentiating between models that use different initial conditions, constraining further the value of $\eta/s$ and allowing to decouple the influence of the late hadronic stage from the hydrodynamic evolution of the system.
Categories: nucl-ex