Abstract
Hadronic observables in the final stage of heavy ion collision can be described well by fluid dynamics or blast wave parameterizations. We improve existing blast wave models by adding shear viscous corrections to the particle distributions in the Navier-Stokes approximation. The specific shear viscosity η/s of a hadron gas at the freeze-out temperature is a new parameter in this model. We extract the blast wave parameters with viscous corrections from experimental data which leads to constraints on the specific shear viscosity at kinetic freeze-out. Preliminary results show η/s is rather small.
Highlights
In the initial stage of heavy-ion collisions, a hot and dense fireball is created
At the kinetic freeze-out fluid cells are translated into particles through the Cooper-Frye formula
We use the parameterization vT = αρn, α = α0 + α2 cos 2φb where α is the surface velocity, α0 is the average surface velocity, α2 is an elliptic deformation of the flow field and n is a power term
Summary
In the initial stage of heavy-ion collisions, a hot and dense fireball is created. The fireball cools rapidly and expands into the surrounding vacuum. Hadronic observables in the final stage of the heavy-ion collisions can be described well by fluid dynamics or blast wave parameterizations. In this contribution, we construct a blast wave model with viscous corrections by calculating the viscous stress tensor from the parameterized flow field in the Navier-Stokes approximation, similar to the models developed in [1][2]. 2. Viscous Corrections In Fluid Dynamics And Blast Wave Fluid dynamics models the time evolution of the nuclear matter in heavy ion collisions, determined by initial conditions and the equation of state. Extractions of η/s from data using viscous fluid dynamics conflate the effects of shear viscosity on the dynamical evolution and on freeze-out This is to some extent true in calculations that switch to a hadronic transport model for freeze-out. It becomes sensitive to η/s at kinetic freeze-out only
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
