Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Fast pattern recognition with the ATLAS L1 track trigger for the HL-LHC
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics. (ATLAS)ORCID iD: 0000-0002-7288-3610
2017 (English)In: PoS - Proceedings of Science, ISSN 1824-8039, E-ISSN 1824-8039, Vol. Vertex2016, p. 69-Article in journal (Refereed) Published
Abstract [en]

A fast hardware based track trigger is being developed in ATLAS for the High Luminosity upgrade of the Large Hadron Collider. The goal is to achieve trigger levels in the high pile-up conditions of the High Luminosity Large Hadron Collider that are similar or better than those achieved at low pile-up conditions by adding tracking information to the ATLAS hardware trigger. A method for fast pattern recognition using the Hough transform is investigated. In this method, detector hits are mapped onto a 2D parameter space with one parameter related to the transverse momentum and one to the initial track direction. The performance of the Hough transform is studied at different pile-up values. It is also compared, using full event simulation of events with average pile-up of 200, with a method based on matching detector hits to pattern banks of simulated tracks stored in a custom made Associative Memory ASICs. The pattern recognition is followed by a track fitting step which calculates the track parameters. The speed and precision of the track fitting depends on the quality of the hits selected by the pattern recognition step. The figures of merit of the pattern recognition are measured by the efficiency for finding hits from high transverse momentum tracks and the power of rejecting hits from low transverse momentum tracks and fake tracks.

Place, publisher, year, edition, pages
2017. Vol. Vertex2016, p. 69-
National Category
Subatomic Physics
Identifiers
URN: urn:nbn:se:uu:diva-390268DOI: 10.22323/1.287.0069OAI: oai:DiVA.org:uu-390268DiVA, id: diva2:1341239
Conference
C16-09-26
Available from: 2019-08-08 Created: 2019-08-08 Last updated: 2019-08-22Bibliographically approved
In thesis
1. A search for leptoquarks with the ATLAS detector and hardware tracking at the High-Luminosity LHC
Open this publication in new window or tab >>A search for leptoquarks with the ATLAS detector and hardware tracking at the High-Luminosity LHC
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis presents a search for pair-production of scalar leptoquarks, decaying into third-generation particles, using proton-proton collisions delivered by the Large Hadron Collider (LHC) and recorded by the ATLAS detector. It also presents the development of a hardware track trigger for the Phase-II upgrade of the ATLAS experiment.

The search for pair-production of leptoquarks is performed using data collected by the ATLAS detector in 2015 and 2016 at a center-of-mass energy of 13 TeV. The total integrated luminosity of this data set amounts to 36.1 fb−1 . The search sensitivity is optimized for up-type leptoquarks where both leptoquarks decay to a b-quark and a τ -lepton. However, it also proves sensitive to down-type leptoquarks where both leptoquarks decay to a top-quark and a τ -lepton. The data is found to be compatible with the Standard Model, so exclusion limits are set on the leptoquark mass.

After the High Luminosity upgrade of the LHC, the ATLAS detector faces a 5–7 times increase in the number of simultaneous proton-proton collisions. To benefit from this increase in luminosity, the ATLAS detector has to maintain low trigger thresholds while keeping manageable trigger rates. A crucial part of the solution is the development of Hardware Tracking for the Trigger (HTT). The HTT first selects hit clusters in the inner tracking detector using associative memories and uses the selected clusters to perform linearized track-fits. This thesis presents the HTT system with focus on using the Hough transform as an alternative to associative memories to select clusters in the inner detector. The performance of the Hough transform is studied and a hardware implementation is discussed.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2019. p. 123
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1833
Keywords
Leptoquarks, Hough transform, LHC, ATLAS, HL-LHC, Particle physics, Particle tracking, Cluster finding, Trigger
National Category
Subatomic Physics
Research subject
Physics with specialization in Elementary Particle Physics
Identifiers
urn:nbn:se:uu:diva-390352 (URN)978-91-513-0707-7 (ISBN)
Public defence
2019-09-27, Polhemsalen, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 13:15 (English)
Opponent
Supervisors
Available from: 2019-09-04 Created: 2019-08-08 Last updated: 2019-09-17

Open Access in DiVA

fulltext(311 kB)34 downloads
File information
File name FULLTEXT01.pdfFile size 311 kBChecksum SHA-512
15dc447f5a8a5bd06f7608cb681672d18b54285e56d28e16a983c468999d4be939c09347a257ae948ecb9bc9f1fe9026a7534ca6372f059cc9b3cb41a27e97c8
Type fulltextMimetype application/pdf

Other links

Publisher's full text

Search in DiVA

By author/editor
Mårtensson, Mikael
By organisation
High Energy Physics
In the same journal
PoS - Proceedings of Science
Subatomic Physics

Search outside of DiVA

GoogleGoogle Scholar
Total: 34 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 47 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf