Rapidity-dependent eccentricity scaling in relativistic heavy-ion collisions

Abstract

There is a well-established relation between the spatial asymmetry in the initial stage of a heavy-ion collision and the final momentum anisotropy, which allows for a separation of effects from initial conditions vs. later evolution and has proved exceptionally powerful. However, until recently it has only been studied in two dimensions -- either through boost-invariant simulations or studying only quantities at mid-rapidity. We explore an extension to 3 dimensions, in order to determine whether a similar understanding can be obtained for the rapidity dependence of the collision system. In particular, we introduce rapidity-dependent eccentricities and investigate a trivial extension of the 2D eccentricity scaling of elliptic and triangular flow, as well as a way to systematically improve these initial-state estimators. We then explore the dependence of the resulting response coefficients on shear viscosity and initial total energy.

7 pages, 10 figures; v2: addition of Appendix B with discussion about another possible term in gradient expansion of eccentricities, version accepted for publication

References in corpus (2)

• Elliptic and triangular flow in event-by-event (3+1)D viscous hydrodynamics
• Triangularity and Dipole Asymmetry in Heavy Ion Collisions

Cited by in corpus (4)

• A collision geometry-based 3D initial condition for relativistic heavy-ion collisions
• Progress and Challenges in Small Systems
• Probing the structure of the initial state of heavy-ion collisions with $p_T$-dependent flow fluctuations
• Longitudinal fluid response and pseudorapidity dependent flow in relativistic heavy-ion collisions