Research at the energy frontier with the ATLAS Detector
Analysis of ATLAS data
The Large Hadron Collider just outside Geneva, Switzerland, is delivering high energy proton-proton collisions that are being recorded by the ATLAS detector. During the Run-2 data taking period that ended in late 2018, we collected a very large new dataset of such collisions. Through analysis of this data, we can expand our knowledge of the fundamental nature of our world. One of the topics that will be investigated is studies of the Higgs boson that was discovered in 2012.
This summer project involves analysis of the ATLAS data. Possible tasks are to explore kinematic and production properties of the Higgs boson in events where it decays either to two photons or to four leptons, or other physics processes. In preparation for the Run-3 data taking period scheduled for 2021, one will need to revise the Higgs-boson analysis strategy and improve on the reconstruction of electromagnetic (electrons, photons) and hadronic (jets) detector objects that form the main signatures for the Higgs boson detection. This work will include working both with Monte Carlo simulated collisions and with the actual LHC data. As part of this project, improvements of the ATLAS reconstruction will be investigated that might aid future discoveries.
Characterization of the electrical properties of silicon sensors for the ATLAS detector upgrade at the LHC
In 2024-2025, the Large Hadron Collider and the ATLAS detector will undergo major upgrades to prepare for the High Luminosity LHC (HL-LHC) that will start in about 2026. HL-LHC will operate at a significantly higher intensity: the instantaneous luminosity of the proton beams will be seven times that of the design criteria. This significantly enhances the overall physics potential, but also makes the experimental conditions harsher and more challenging. The entire inner tracking detector of ATLAS will need to be replaced with a new silicon Inner Tracker detector (ITk) to cope with this situation.
The particle physics group at Carleton University is actively working on this detector upgrade, and is looking for interested students to work on the characterization and performance evaluation of the prototype ITk detector sensors. This work will include the study of the state-of-the-art thin silicon sensors, as well as specially designed test structures that will be probed by dedicated equipment in order to understand their physics performance under carefully controlled environmental conditions. As a separate task, the analog and digital characterization of radiation-hard single ABCstar readout chips will also be performed. Both projects will require the development of the required experimental setups, including LabView-based readout and control software, as well as C++-based analysis of the measurement data. For the ABCstar project, some prior familiarity with electronic evaluation boards and/or FPGA programming, will be considered an asset.
Small-strip Thin Gap Chambers (sTGC) for the NSW
The LHC is scheduled to be upgraded over the next decade in order to increase its energy and rate collisions. Parts of ATLAS will suffer degraded performance at these higher luminosities, and will require improvements, for example, to address both the increased single-muon trigger rates and the degraded muon track reconstruction performance. This will be provided by the introduction of a new detector called the New Small Wheel (NSW) in the end-cap region of the muon spectrometer to replace the existing detector modules. The NSW is a set of precision tracking and trigger chambers that are able to work at high rates with excellent real-time spatial and temporal resolution.
The Carleton University ATLAS group is one of the leading Canadian institutions in the fabrication of small-strip Thin Gap Chambers (sTGC) for the NSW. The summer student engaged with the NSW project can participate in two ways:
Either work at the assembly of the sTGC wedges and at the deployment of the NSW alignment system, or work at development of the calibration method of the electronics and at the measurement of the timing and spatial resolutions of the sTGC. Both projects require travel to CERN for a two-month period with the IPP CERN Summer Program. The skills that will be developed working on the NSW are directly applicable to the leading edge physics exploration and data mining at the LHC. In addition the students will acquire valuable experience by working together with senior graduate students, research associates and skilled professionals that have long experience in designing and operating laboratory and detector systems at CERN. The student will also be part of the larger ATLAS-Canada group.
For more information on the ATLAS project at Carleton University, please consult http://physics.carleton.ca/atlas/
Professor Alain Bellerive (alainb
physics [dot] carleton [dot] ca)
Professor Dag Gillberg (dag [dot] gillberg cern [dot] ch)
Professor Jesse Heilman (heilman physics [dot] carleton [dot] ca)
Professor Thomas Koffas (Thomas [dot] Koffas carleton [dot] ca)