Hydrodynamic fluctuations near a critical endpoint and Hanbury-Brown–Twiss interferometry

The field of high-energy nuclear collisions has witnessed a surge of interest in the role played by hydrodynamic fluctuations. Hydrodynamic fluctuations may have significant effects on matter created in heavy-ion accelerators whose trajectories in the plane of temperature versus chemical potential pass near a possible critical endpoint. We extend previous studies to explore the impact of these fluctuations on Hanbury-Brown–Twiss interferometry of identical hadrons. With an appropriately defined correlation function we find that the fluctuations increase substantially when the trajectory passes near a critical endpoint and also displays a damped oscillatory behavior in the rapidity distance $\mathrm{\Delta }y$ unlike that originating from initial-state fluctuations.