Preliminary Results on Direct Photon-Photon HBT Measurements in $\sqrt{s_{\mathrm{NN}}}$ = 62.4 GeV and 200 GeV Au+Au Collisions at RHIC

Abstract

We present the preliminary results on direct photon interferometry measurements in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 62.4 and 200 GeV using the STAR (Solenoidal Tracker at RHIC) detector. Photons are reconstructed via $e^{+}/e^{-}$ conversions in STAR Time Projection Chamber(TPC) and energy deposited by photons in STAR Barrel Electromagnetic Calorimeter(BEMC). The two-photon correlations are measured using (1) both photons measured using BEMC; (2) one photon from conversions and the other measured with BEMC. Both the methodologies and the possible constraints in the correlation function measurements are discussed.

for the STAR Collaboration. 7 pages 2 figures Poster presented at 18th International Conference on Ultrarelativistic Nucleus-Nucleus Collisions: Quark Matter 2005 (QM 2005), Budapest, Hungary, 4-9 Aug 2005. To be published in NUKLEONIKA, Polish Scientific Journal