A new method to distinguish hadronically decaying boosted Z bosons from W bosons using the ATLAS detector



Aad, G, Abbott, B, Abdallah, J, Abdinov, O, Aben, R, Abolins, M, AbouZeid, OS, Abramowicz, H, Abreu, H, Abreu, R
et al (show 2846 more authors) (2016) A new method to distinguish hadronically decaying boosted Z bosons from W bosons using the ATLAS detector EUROPEAN PHYSICAL JOURNAL C, 76 (5). 238-. ISSN 1434-6044, 1434-6052

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Abstract

The distribution of particles inside hadronic jets produced in the decay of boosted W and Z bosons can be used to discriminate such jets from the continuum background. Given that a jet has been identified as likely resulting from the hadronic decay of a boosted W or Z boson, this paper presents a technique for further differentiating Z bosons from W bosons. The variables used are jet mass, jet charge, and a b-tagging discriminant. A likelihood tagger is constructed from these variables and tested in the simulation of W<sup>′</sup>→ WZ for bosons in the transverse momentum range 200 GeV < <inf>pT</inf>< 400 GeV in s= 8 TeV pp collisions with the ATLAS detector at the LHC. For Z-boson tagging efficiencies of <inf>ϵZ</inf>= 90 , 50, and 10 % , one can achieve W<sup>+</sup>-boson tagging rejection factors (1 / <inf>ϵW<sup>+</sup> </inf>) of 1.7, 8.3 and 1000, respectively. It is not possible to measure these efficiencies in the data due to the lack of a pure sample of high <inf>pT</inf>, hadronically decaying Z bosons. However, the modelling of the tagger inputs for boosted W bosons is studied in data using a tt¯ -enriched sample of events in 20.3 fb<sup>- 1</sup> of data at s= 8 TeV. The inputs are well modelled within uncertainties, which builds confidence in the expected tagger performance.

Item Type: Article
Additional Information: 32 pages plus author list (49 pages total), 19 figures, published version, all figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/PERF-2015-02/
Uncontrolled Keywords: Atlas Collaboration, Atlas Collaboration, Atlas Collaboration
Depositing User: Symplectic Admin
Date Deposited: 21 Feb 2017 14:25
Last Modified: 24 Jun 2026 17:19
DOI: 10.1140/epjc/s10052-016-4065-1
Related Websites:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3005952
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