Characterisation and mitigation of beam-induced backgrounds observed in the ATLAS detector during the 2011 proton-proton run

Unknown, Article, Preprint English OPEN
Onofre, A. ; Castro, Nuno Filipe Silva Fernandes ; ATLAS Collaboration (2013)
  • Publisher: IOP Publishing
  • Journal: (issn: 1748-0221, vol: 8, pp: 7,004-7,004)
  • Related identifiers: doi: 10.1088/1748-0221/8/07/P07004, doi: 10.1088/1748-0221/8/07/p07004, doi: 10.7892/boris.58447
  • Subject: Accelerator modelling and simulations (multi-particle dynamics | single-particle dynamics) | Particle Physics - Experiment | Naturvetenskap | Performance of High Energy Physics Detectors | Accelerator modelling and simulations (multi-particle dynamics; Analysis and statistical methods; Pattern recognition, cluster finding, calibration and fitting methods; Performance of High Energy Physics Detectors; single-particle dynamics) | Pattern recognition, cluster finding, calibration and fitting methods | 530 | QC | Física | Science & Technology | Settore FIS/01 - Fisica Sperimentale | High Energy Physics - Experiment | Settore FIS/04 - Fisica Nucleare e Subnucleare | Natural Sciences | Accelerator modelling and simulations (multi-particle dynamics; single-particle dynamics) | 530 Physics | Pattern recognition; cluster finding; calibration and fitting methods; Performance of High Energy Physics Detectors; Accelerator modelling and simulations (multi-particle dynamics; single-particle dynamics); Analysis and statistical methods | Analysis and statistical methods
    • ddc: ddc:610
    arxiv: Physics::Instrumentation and Detectors | Physics::Accelerator Physics

This paper presents a summary of beam-induced backgrounds observed in the ATLAS detector and discusses methods to tag and remove background contaminated events in data. Trigger-rate based monitoring of beam-related backgrounds is presented. The correlations of backgrounds with machine conditions, such as residual pressure in the beam-pipe, are discussed. Results from dedicated beam-background simulations are shown, and their qualitative agreement with data is evaluated. Data taken during the passage of unpaired, i.e. non-colliding, proton bunches is used to obtain background-enriched data samples. These are used to identify characteristic features of beam-induced backgrounds, which then are exploited to develop dedicated background tagging tools. These tools, based on observables in the Pixel detector, the muon spectrometer and the calorimeters, are described in detail and their efficiencies are evaluated. Finally an example of an application of these techniques to a monojet analysis is given, which demonstrates the importance of such event cleaning techniques for some new physics searches. This paper presents a summary of beam-induced backgrounds observed in the ATLAS detector and discusses methods to tag and remove background contaminated events in data. Trigger-rate based monitoring of beam-related backgrounds is presented. The correlations of backgrounds with machine conditions, such as residual pressure in the beam-pipe, are discussed. Results from dedicated beam-background simulations are shown, and their qualitative agreement with data is evaluated. Data taken during the passage of unpaired, i.e. non-colliding, proton bunches is used to obtain background-enriched data samples. These are used to identify characteristic features of beam-induced backgrounds, which then are exploited to develop dedicated background tagging tools. These tools, based on observables in the Pixel detector, the muon spectrometer and the calorimeters, are described in detail and their efficiencies are evaluated. Finally an example of an application of these techniques to a monojet analysis is given, which demonstrates the importance of such event cleaning techniques for some new physics searches. This paper presents a summary of beam-induced backgroundsobserved in the ATLAS detector and discusses methods to tag andremove background contaminated events in data. Trigger-rate basedmonitoring of beam-related backgrounds is presented. Thecorrelations of backgrounds with machine conditions, such asresidual pressure in the beam-pipe, are discussed. Results fromdedicated beam-background simulations are shown, and theirqualitative agreement with data is evaluated. Data taken during thepassage of unpaired, i.e. non-colliding, proton bunches is used toobtain background-enriched data samples. These are used to identifycharacteristic features of beam-induced backgrounds, which then areexploited to develop dedicated background tagging tools. Thesetools, based on observables in the Pixel detector, the muonspectrometer and the calorimeters, are described in detail and theirefficiencies are evaluated. Finally an example of an application ofthese techniques to a monojet analysis is given, which demonstratesthe importance of such event cleaning techniques for some newphysics searches.
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