Year: 2026
Type: preprint
Abstract: We present the first study of shear viscosity induced cavitation incorporating transverse expansion alongside chemical non-equilibrium dynamics in the Quark-Gluon Plasma (QGP). Chemical non-equilibrium is incorporated through quark and gluon fugacities, whose evolution is coupled to causal dissipative relativistic hydrodynamics in the Gubser geometry. Using phenomenological temperature-dependent shear viscosity parametrizations, we study the evolution of the longitudinal pressure and identify the conditions under which it becomes negative and thereby breaking down the hydrodynamic description. We demonstrate that shear induced cavitation develops first at the centre of the fireball ($r=0$) at early times and subsequently extends towards larger radial distances, with transverse expansion accelerating its onset, while persisting during chemical equilibration. Within our framework, we determine the critical initial shear viscosity $(η/s)_{\rm crit}$, below which cavitation does not occur throughout the QGP evolution. Since hydrodynamics is found to successfully describe the phenomenology of heavy-ion collisions, our results provide a constraint on shear viscosity requiring the absence of cavitation during the QGP evolution. We find that the phenomenologically extracted $η/s$ from JETSCAPE analyses lie below the critical shear viscosity $(η/s)_{\rm crit}$ obtained in our framework.
Source: arXiv (Cornell University)
Authors: Naik, Lakshmi J., Sreekanth, V.
Institution: Amrita Vishwa Vidyapeetham
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7214019531