Jun 17 – 21, 2019
Europe/Budapest timezone

Observation of a non-monotonic s-dependence of initial energy densities at RHIC and LHC

Jun 18, 2019, 5:20 PM


Prof. Tamás Csörgő (Wigner RCP and EKE KRC, Budapest and Gyöngyös)


We discuss a recently found family of exact and analytic, finite and accelerating, 1+1 dimensional solutions of perfect fluid relativistic hydrodynamics to describe the pseudorapidity densities and longitudinal HBT-radii and to estimate the lifetime parameter and the initial energy density of the expanding fireball in symmetric heavy ion collisions at RHIC and LHC energies. From these exact solutions of relativistic hydrodynamics, we derive a simple and powerful formula to describe the pseudorapidity density distributions in high energy proton-proton and heavy ion collisions, and derive the scaling of the longitudinal HBT radius parameter as a function of the pseudorapidity density. We improve upon several oversimplifications in Bjorken's famous initial energy density estimate, and apply our results to estimate the initial energy densities of high energy reactions with data-driven pseudorapidity distributions. When compared to similar estimates at the LHC energies, our results indicate a surprising and non-monotonic dependence of the initial energy density on the energy of heavy ion collisions at RHIC.

Primary authors

Prof. Tamás Csörgő (Wigner RCP and EKE KRC, Budapest and Gyöngyös) Mr Gábor Kasza (Wigner RCP, Budapest, Hungary)

Presentation materials