Physical Review C 70,4 (2004) 044902;
We report inclusive photon measurements about midrapidity (\y\<0.5) from Au-197+Au-197 collisions at roots(NN)=130 GeV at RHIC. Photon pair conversions were reconstructed from electron and positron tracks measured with the Time Projection Chamber (TPC) of the STAR experiment. With this method, an energy resolution of DeltaE/Eapproximate to2% at 0.5 GeV has been achieved. Reconstructed photons have also been used to measure the transverse momentum (p(t)) spectra of pi(0) mesons about midrapidity (\y\<1) via the pi(0)-->gammagamma decay channel. The fractional contribution of the pi(0)-->gammagamma decay to the inclusive photon spectrum decreases by 20%+/-5% between p(t)=1.65 GeV/c and p(t)=2.4 GeV/c in the most central events, indicating that relative to pi(0)-->gammagamma decay the contribution of other photon sources is substantially increasing.
heavy-ion collisions;; quark-gluon plasma;; star;; flow
Date of this Version