Phenomenological Consequences of Enhanced Bulk Viscosity Near the QCD Critical Point

Understand

In the proximity of the QCD critical point the bulk viscosity of quark-gluon matter is expected to be proportional to nearly the third power of the critical correlation length, and become significantly enhanced.

• This work is the first attempt to study the phenomenological consequences of enhanced bulk viscosity near the QCD critical point.
• For this purpose, we implement the expected critical behavior of the bulk viscosity within a non-boost-invariant, longitudinally expanding $1+1$ dimensional causal relativistic hydrodynamical evolution at non-zero baryon density.
• We demonstrate that the critically-enhanced bulk viscosity induces a substantial non-equilibrium pressure, effectively softening the equation of state, and leads to sizable effects in the flow velocity and single particle distributions at the freeze-out.