In the high energy environment of the Large Hadron Collider, there is a finite probability for the longitudinal tail of the hadronic shower represented by a jet to leak out of the calorimeter, commonly referred to as longitudinal hadronic shower leakage, or jet 'punchthrough'. This thesis prescribes a method for identifying such 'punch-through' jets via the use of muon activity found behind a jet in the ATLAS muon spectrometer, finding an occurrence rate of up to 18% in the worst affected regions. 'Punch-through' jets were found to degrade the measured jet energy scale by up to 30%, and jet energy resolution by a factor of 3. A correction to remove these effects was developed in Monte Carlo and validated in data, with associated systematic uncertainties derived. The correction was found to negate the degradation of the measured jet energy scale, improving the jet energy resolution by up to 10% in the worst affected regions, and up to 1.6% overall. The correction was integrated into the final 2012 ATLAS jet energy calibration scheme as the fifth step of the Global Sequential corrections. The prescription developed in this thesis to derive the correction is currently being used by ATLAS in Run II of the Large Hadron Collider.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:730522 |
| Date | January 2015 |
| Creators | Gupta, Shaun |
| Contributors | Issever, Cigdem |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://ora.ox.ac.uk/objects/uuid:3f37bd18-d4d2-40c5-b231-e193060ec218 |
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