Unlocking "imprints" of conserved charges in the initial state of heavy-ion collisions

TL;DR

This paper introduces new flow observables in heavy-ion collisions that are sensitive to initial conserved charge fluctuations, offering a novel way to probe the initial state of the medium formed in such collisions.

Contribution

It proposes a new set of anisotropic flow observables specifically designed to detect initial BSQ charge fluctuations in heavy-ion collisions.

Findings

New observables are sensitive to initial charge fluctuations up to ~10%.

Hydrodynamic simulations show measurable effects of initial BSQ fluctuations.

Experimental tests can validate the initial state models.

Abstract

Hydrodynamic approaches to modeling relativistic high-energy heavy-ion collisions are based on the conservation of energy and momentum. However, the medium formed in these collisions also carries additional conserved quantities, including baryon number (B), strangeness (S), and electric charge (Q). In this Letter, we propose a new set of anisotropic flow observables designed to be exclusively sensitive to the effects of conserved BSQ charge fluctuations, providing insight into the initial state. Using the recently developed hydrodynamic framework \iccing{}+\ccake{}, we show that these new observables provide a measurable effect of initial BSQ charge fluctuations (ranging up to $\sim $10\%), which can be tested by experiments.