We suggest using the azimuthal distribution of mean transverse (radial) rapidity of final state particles, rather than the standard azimuthal multiplicity distribution, as a more direct measure of the transverse motion of the source. Using a sample generated by the AMPT model with string melting, we demonstrate that the azimuthal amplitude of the suggested distribution characterizes the anisotropic radial flow and coincides with the parameter of anisotropic radial rapid...
