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


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Aad G., Abbott B., Abdallah J., Abdinov O., Aben R., Abolins M., ...Daha Fazla

EUROPEAN PHYSICAL JOURNAL C, cilt.76, sa.5, 2016 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 76 Sayı: 5
  • Basım Tarihi: 2016
  • Doi Numarası: 10.1140/epjc/s10052-016-4065-1
  • Dergi Adı: EUROPEAN PHYSICAL JOURNAL C
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Gazi Üniversitesi Adresli: Hayır

Özet

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' -> WZ for bosons in the transverse momentum range 200 GeV < p(T) < 400 GeV in root s = 8 TeV pp collisions with the ATLAS detector at the LHC. For Z-boson tagging efficiencies of epsilon(Z) = 90, 50, and 10 %, one can achieve W+-boson tagging rejection factors (1/epsilon(W+)) 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 p(T), hadronically decaying Z bosons. However, the modelling of the tagger inputs for boosted W bosons is studied in data using a t (t) over bar -enriched sample of events in 20.3 fb(-1) of data at root s = 8 TeV. The inputs are well modelled within uncertainties, which builds confidence in the expected tagger performance.