Correlation coefficient between harmonic flow and transverse momentum in heavy-ion collisions

The correlation between the harmonic flow and the transverse momentum in relativistic heavy ion collisions is calculated in the hydrodynamic model. The partial correlation coefficient, corrected for fluctuations of multiplicity, is compared to experimental data. Estimators of the final transverse momentum and harmonic flow are used to predict the value of the correlation coefficient from the moments of the initial distribution. A good description of the hydrodynamic simulation results is obtained if the estimator for the final transverse momentum, besides the transverse size and the entropy, includes also the eccentricities.