Finite size of hadrons and HBT interferometry for hydrodynamic sources

Hadrons formed in heavy-ion collisions are not point-like objects, they cannot occupy too close space-time points. When the two bosons are too close to each other, their constituents start to mix and they cannot be considered as bosons subjected to Bose–Einstein statistics, this effect is called the excluded volume effect. We study the excluded volume effect on Hanbury Brown–Twiss (HBT) for the sources with various sizes. The effect on HBT was shown in out, side and long directions, and it is more obvious for the source with a narrow space-time distribution. The correlation functions for high transverse momenta are more suppressed by the excluded volume effect.

HBT Radii: Comparative Studies on Collision Systems and Beam Energies

Two-particle Hanbury-Brown-Twiss (HBT) interferometry is an important probe for understanding the space-time structure of particle emission sources in high energy heavy ion collisions. We present the comparative studies of HBT radii in Pb+Pb collisions at sNN = 17.3 GeV with Au+Au collisions at sNN = 19.6 GeV. To further understand this specific energy regime, we also compare the HBT radii for Au+Au collisions at sNN = 19.6 GeV with Cu+Cu collisions at sNN = 22.4 GeV. We have found interesting similarity in the Rout/Rside ratio with mT across the collision systems while comparing the data for this specific energy zone which is interesting as it acts as a bridge from SPS energy regime to the RHIC energy domain.