Direct gamma and gamma-jet measurement capability of ATLAS for Pb+Pb collisions

Abstract

The ATLAS detector at the LHC is capable of efficiently separating photons and neutral hadrons based on their shower shapes over a wide range in eta, phi, ET, either in addition to or instead of isolation cuts. This provides ATLAS with a unique strength for direct photon and gamma-jet physics as well as access to the unique capability to measure non-isolated photons from fragmentation or from the medium. We present a first look at the ATLAS direct photon measurement capabilities in Pb+Pb and, for reference, p+p collisions at sqrt(sNN)=5.5 TeV over the region |eta|<2.4.Comment: 4 pages, 4 figures - To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, 2009, updated to remove draft linenumbering. No other change