2004/01/08 by STAR Collaboration, J. R. Adams, C. Adler +97 · 1 citation
Physics and Astronomy · #Atomic physics #Electron #Hadron #High-Energy Particle Collisions Research #Meson #Momentum (technical analysis) #Nuclear physics #Optics #Particle physics #Particle physics theoretical and experimental studies #Photon #Photon energy #Physics #Pion #Positron #Production (economics) #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Rapidity #Spectral line #nucl-ex
paper · pdf · doi:10.1103/physrevc.70.044902
published as Phys.Rev.C70:044902,2004 · 13 pages, 14 figures, submitted to Phys. Rev. C
arxiv created 2004/01/08 · openalex publication_date 2004/10/11 · arxiv updated 2012/08/27 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report inclusive photon measurements about midrapidity (\ensuremath|y\ensuremath|<0.5) from 197Au+197Au collisions at √sNN=130\phantom\rule0.3em0exGeV 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 \ensuremathΔE∕E\ensuremath≈2% at 0.5\phantom\rule0.3em0exGeV has been achieved. Reconstructed photons have also been used to measure the transverse momentum (pt) spectra of \ensuremathπ0 mesons about midrapidity (\ensuremath|y\ensuremath|<1) via the \ensuremathπ0\ensuremath→\ensuremathγ\ensuremathγ decay channel. The fractional contribution of the \ensuremathπ0\ensuremath→\ensuremathγ\ensuremathγ decay to the inclusive photon spectrum decreases by 20%\ifmmode±\else\textpm\fi5% between pt=1.65\phantom\rule0.3em0exGeV∕c and pt=2.4\phantom\rule0.3em0exGeV∕c in the most central events, indicating that relative to \ensuremathπ0\ensuremath→\ensuremathγ\ensuremathγ decay the contribution of other photon sources is substantially increasing.