Decomposition of fluctuating initial conditions and flow harmonics

Understand

Collective flow observed in heavy ion collisions is largely attributed to initial geometrical fluctuations, and it is the hydrodynamic evolution of the system that transforms those initial spatial irregularities into final state momentum anisotropies.

• Cumulant analysis provides a mathematical tool to decompose those initial fluctuations in terms of radial and azimuthal components.
• It is usually thought that a specified order of azimuthal cumulant, for the most part, linearly produces flow harmonic of the same order.
• In this work, we carry out a systematic study on the connection between cumulants and flow harmonics using a hydrodynamic code called NeXSPheRIO.