Search for Microscopic Black Holes in Multi-Jet Final-States using Multiple Single-Jet Triggers with ATLAS Detector with 8 TeV Proton-Proton Collisions at the Large Hadron Collider

• Author / Creator

  Butt, Aatif I

• Higher dimensional microscopic black holes may be produced in particle accelerators at high energies which will emit a high multiplicity of Standard Model (SM) particles via thermal decay. This thesis documents a search for higher dimensional microscopic black holes in multi-jet final-states using six single-jet triggers with the ATLAS detector with 8 TeV proton-proton collisions at the Large Hadron Collider. The ATLAS 2012 data corresponds to a total integrated luminosity of 20.3~fb$^{-1}$. The background topology in this search consists of all multi-jet final-states from all SM processes. Quantum Chromodynamics (QCD) processes contribute maximally to the SM multi-jet final-states and dominate this background topology. The invariant mass (M) and scalar sum of transverse momenta of all jets (HT) in events are used as analysis variables. The M and HT distributions for ATLAS data are consistent with QCD predictions of two well known hadronization models (PYTHIA8 and HERWIG++) for each single-jet trigger. Counting experiments are performed to set model-independent upper limits (at 95% confidence level) on the production cross section times acceptance times efficiency of new physics in multi-jet events. The model-independent upper limit on the production cross section times acceptance times efficiency is 0.15 fb for the threshold mass M{th}>4.5 TeV. Model-dependent production cross section limits (at 95% confidence level) are also calculated versus M{th} and fundamental Planck mass M_{D} for non-rotating and rotating black holes for two, four and six large extra dimensions.

• Subjects / Keywords

  • Microscopic Black Holes
  • ATLAS Detector
  • Large Hadron Collider
  • 8 TeV Proton-Proton Collisions

• Graduation date

  Fall 2016

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R31834C90

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.