Speaker
Dr
Song Zhang
(Shanghai Institute of Applied Physics, CAS)
Description
The ultra-relativistic heavy ion collisions aim at forming the quark-gluon plasma (QGP) and presenting properties of QGP phase transition. The fireball created in the ultra-relativistic heavy ion collisions will reach kinetic freeze-out stage from the initial ultra-hot-dense state. The temperature, system size and lifetime, and expansion velocity at radial direction may inherit some properties of the QGP phase transition. HBT correlation function can provides the system evolution information, such as system size parameters, system lifetime. By fitting the HBT correlation radii in the blast-wave model, the system size and lifetime are presented with the kinetic temperature and radial flow extracted from transverse momentum distribution measured in experiments. The beam-energy dependence of HBT radii significantly depends on the range of the system size parameter and system lifetime. And we also find the blast-wave can describe transverse momentum dependence of HBT correlation radii (Rside, Rout and Rlong) at LHC energy with same fixed parameters but it failed to fit Rlong while fitting Rside and Rout successfully at RHIC top energy with the same fixed parameters. This implies the different evolution mechanism for LHC and RHIC energy and suggests a long system lifetime for the fireball created at LHC energy.
Author
Dr
Song Zhang
(Shanghai Institute of Applied Physics, CAS)
