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 $\sqrt{s_{\mathrm{N}\mathrm{N}}}$ = 17.3 GeV with Au+Au collisions at $\sqrt{s_{\mathrm{N}\mathrm{N}}}$ = 19.6 GeV. To further our understanding for this specific energy regime we also compare the HBT radii for Au+Au collisions at $\sqrt{s_{\mathrm{N}\mathrm{N}}}$ = 19.6 GeV with Cu+Cu collisions at $\sqrt{s_{\mathrm{N}\mathrm{N}}}$ = 22.4 GeV. We have found interesting similarity in the $R_{\rm out}/R_{\rm side}$ratiowith$m_{\rm T}$ 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.