A Topological Clustering Algorithm for the ATLAS Level-1 Calorimeter Trigger Upgrades

POSTER

Abstract

Topological clustering is the current method for calorimeter object reconstruction and suppression of multiple interactions per crossing (pileup) in the ATLAS detector at the Large Hadron Collider. We present simulation studies adopting this technique for the Level-1 Calorimeter trigger in the Phase-I and Phase-II upgrades of the trigger electronics. Applying a modified topological clustering algorithm to the 0.2x0.2 (in eta-phi) towers of the global feature extractor (gFEX), a component of the Level-1 trigger system for the Phase-I upgrade, we aim to improve the performance of the jet and missing transverse energy triggers. In particular, we focus on reconstructing so-called ``boosted'' objects, whose transverse momenta are large compared to their masses. The results of these studies are also applicable to a potential dedicated module with access to the full calorimeter granularity that may be implemented in the Phase-II upgrade.

Authors

  • Luc Lisi

    Univ of Oregon

  • Elliot Parrish

    Univ of Oregon

  • Bethany Mathews

    International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Bangalore, India, Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Potsdam-Golm, Germany, Univ of Idaho, Washington State University, University of California Berkeley, University of British Columbia, Max Planck Institute for Solid State Research and Ecole Polytechnique F\'ed\'erale de Lausanne, Max Planck Institute for Solid State Research, University of British Columbia and Max Planck Institute for Solid State Research, Physikalisches Institut, Ruprecht-Karls-Universitaet Heidelberg, Univ of Oregon, Whitman College, The University of British Columbia, Durham University, Universit\"at Freiburg, Institute for Nuclear Theory, University of Washington, National Renewable Energy Laboratory, Golden, CO 80401, Los Alamos National Laboratory, Oregon State University

  • Bethany Mathews

    International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Bangalore, India, Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Potsdam-Golm, Germany, Univ of Idaho, Washington State University, University of California Berkeley, University of British Columbia, Max Planck Institute for Solid State Research and Ecole Polytechnique F\'ed\'erale de Lausanne, Max Planck Institute for Solid State Research, University of British Columbia and Max Planck Institute for Solid State Research, Physikalisches Institut, Ruprecht-Karls-Universitaet Heidelberg, Univ of Oregon, Whitman College, The University of British Columbia, Durham University, Universit\"at Freiburg, Institute for Nuclear Theory, University of Washington, National Renewable Energy Laboratory, Golden, CO 80401, Los Alamos National Laboratory, Oregon State University

  • Stephanie Majewski

    Univ of Oregon