Blog
About

8
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Measurement of high p_T isolated prompt photons in lead-lead collisions at sqrt(s_NN)=2.76 TeV with the ATLAS detector at the LHC

      Preprint

      ,

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Prompt photons are a powerful tool to study heavy ion collisions. Their production rates provide access to the initial state parton distribution functions and also provide a means to calibrate the expected energy of jets that are produced in the medium. The ATLAS detector measures photons with its hermetic, longitudinally segmented calorimeter, which gives excellent spatial and energy resolutions, and detailed information about the shower shape of each measured photon. This provides significant rejection against the expected background from the decays of neutral pions in jets. Rejection against jet fragmentation products is further enhanced by requiring candidate photons to be isolated. First results on the spectra of isolated prompt photons from a dataset with an integrated luminosity of approximately 0.13 nb^-1 of lead-lead collisions at sqrt(s_NN)=2.76 TeV are shown as a function of transverse momentum and centrality. The measured spectra are compared to expectations from perturbative QCD calculations.

          Related collections

          Most cited references 2

          • Record: found
          • Abstract: found
          • Article: found
          Is Open Access

          Jet Quenching in the Opposite Direction of a Tagged Photon in High-Energy Heavy-Ion Collisions

          We point out that events associated with large \(E_T\) direct photons in high-energy heavy-ion collisions can be used to study jet energy loss in dense matter. In such events, the \(p_T\) spectrum of charged hadrons from jet fragmentation in the opposite direction of the tagged photon is estimated to be well above the background which can be reliably subtracted at moderately large \(p_T\). We demonstrate that comparison between the extracted fragmentation function in \(AA\) and \(pp\) collisions can be used to determine the jet energy loss and the interaction mean-free-path in the dense matter produced in high-energy heavy-ion collisions.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: found
            Is Open Access

            A new critical study of photon production in hadronic collisions

            In the light of the new prompt photon data collected by PHENIX at RHIC and by D0 at the run II of the Tevatron, we revisit the world prompt photon data, both inclusive and isolated, in hadronic collisions, and compare them with the NLO QCD calculations implemented in the Monte Carlo programme JETPHOX.
              Bookmark

              Author and article information

              Journal
              21 September 2012
              Article
              1209.4910

              http://arxiv.org/licenses/nonexclusive-distrib/1.0/

              Custom metadata
              Proceedings for Hard Probes 2012, May 27 - June 1, 2012, Cagliari, Sardinia, Italy
              hep-ex nucl-ex

              Comments

              Comment on this article