Azimuthal Anisotropy Distributions in High-Energy Collisions

Understand

Elliptic flow in ultrarelativistic heavy-ion collisions results from the hydrodynamic response to the spatial anisotropy of the initial density profile.

• A long-standing problem in the interpretation of flow data is that uncertainties in the initial anisotropy are mingled with uncertainties in the response.
• We argue that the non-Gaussianity of flow fluctuations in small systems can be used to disentangle the initial state from the response.
• We apply this method to recent measurements of anisotropic flow in Pb+Pb and p+Pb collisions at the LHC.