Onset of cavitation in the quark-gluon plasma

Abstract

Abstract:We study the onset of bubble formation (cavitation) in the quark-gluon plasma as a result of the reduction of the effective pressure from bulk-viscous corrections. By calculating velocity gradients in typical models for quark-gluon plasma evolution in heavyion collisions, we obtain results for the critical bulk viscosity above which cavitation occurs. Since present experimental data for heavy-ion collision seems inconsistent with the presence of bubbles above the phase transition temperature of QCD, our results may be interpreted as an upper limit of the bulk viscosity in nature. Our results indicate that bubble formation is consistent with the expectation of hadronisation in low-temperature QCD.

Effects of bulk viscosity and hadronic rescattering in heavy ion collisions at energies available at the BNL Relativistic Heavy Ion Collider and at the CERN Large Hadron Collider

“…For a long time, shear viscosity was considered to be the dominant source of dissipation for the QGP produced in heavy ion collisions [8][9][10][11][12]. Nevertheless, there are theoretical indications that bulk viscosity can become large around the QCD crossover region [13][14][15][16][17] and can significantly affect the evolution of the QGP [18][19][20][21][22]. Early investigations on the effect of bulk viscosity using realistic hydrodynamic simulations often assumed small values for this transport coefficient [23][24][25] and found modest effects.…”

Metric anisotropies and emergent anisotropic hydrodynamics

“…Such large pressure anisotropies indicate large viscous corrections to the distribution function which is contradictory to the near equilibrium assumption of the formulation of viscous hydrodynamic equations. Furthermore, application of traditional linearized viscous hydrodynamics leads to regions of phase space in which the single particle phasespace distribution function may be negative, which may in turn lead to negative longitudinal pressure [27][28][29]. Depending on whether one considers early times or colder regions of the plasma, the size of these unphysical regions increases.…”

Effects of bulk viscosity and hadronic rescattering in heavy ion collisions at RHIC and LHC

“…For a long time, shear viscosity was considered to be the dominant source of dissipation for the QGP produced in heavy ion collisions [8][9][10][11][12]. Nevertheless, there are theoretical indications that bulk viscosity can become large around the QCD crossover region [13][14][15][16][17] and can significantly affect the evolution of the QGP [18][19][20][21][22]. Early investigations on the effect of bulk viscosity using realistic hydrodynamic simulations often assumed small values for this transport coefficient [23][24][25] and found modest effects.…”