Subleading harmonic flows in hydrodynamic simulations of heavy ion collisions

Understand

We perform a principal component analysis (PCA) of $v_3(p_T)$ in event-by-event hydrodynamic simulations of Pb+Pb collisions at the Large Hadron Collider (LHC).

• The PCA procedure identifies two dominant contributions to the two-particle correlation function, which together capture 99.9\% of the squared variance.
• We find that the subleading flow (which is the largest source of flow factorization breaking in hydrodynamics) is predominantly a response to the radial excitations of a third-order eccentricity.
• We present a systematic study of the hydrodynamic response to these radial excitations in 2+1D viscous hydrodynamics.