Diffusion Wake: A Distinctive Consequence of the Mach-Cone Wake Induced by Supersonic Jets in High-Energy Heavy-Ion...

In this Research Perspective, we briefly review the diffusion wake, a distinctive consequence of the Mach-cone wake induced by the supersonic jets in ultrarelativistic heavy-ion collisions. The diffusion wake depletes soft hadrons in the direction opposite to the propagating jet. According to coupled transport and hydrodynamic simulations, a valley in the 2-dimensional jet-hadron correlation in azimuthal angle and rapidity arises on the top of the multiple-parton interaction ridge as an unambiguous signal of the diffusion wake induced by $\gamma$ -jets in heavy-ion collisions. In dijet events with a finite rapidity gap, the rapidity asymmetry of the jet-hadron correlation has been shown to be a robust signal of the diffusion wake. The same rapidity asymmetry can also be applied to $\gamma$ -jet events, and both are background-free. Experimental measurements of these signals can provide valuable insights into the properties of the quark-gluon plasma formed in high-energy heavy-ion collisions.