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Final published version
Licence: CC BY: Creative Commons Attribution 4.0 International License
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - A new method to distinguish hadronically decaying boosted Z bosons from W bosons using the ATLAS detector
AU - Barton, Adam Edward
AU - Beattie, Michael
AU - Borissov, Guennadi
AU - Bouhova-Thacker, Evelina Vassileva
AU - Dearnaley, William
AU - Fox, Harald
AU - Grimm, Kathryn Ann Tschann
AU - Henderson, Robert Charles William
AU - Hughes, Gareth
AU - Jones, Roger William Lewis
AU - Kartvelishvili, Vakhtang
AU - Long, Robin Eamonn
AU - Love, Peter Allan
AU - Maddocks, Harvey
AU - Skinner, Malcolm
AU - Smizanska, Maria
AU - Walder, James William
AU - Wharton, Andy
AU - The ATLAS collaboration
PY - 2016/5/1
Y1 - 2016/5/1
N2 - 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 <pT<<pT< 400 GeV in √s=8 TeV pp collisions with the ATLAS detector at the LHC. For Z-boson tagging efficiencies of ϵZ=90, 50, and 10%, one can achieve W+ -boson tagging rejection factors (1/ϵW+) 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 pT, 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−1 of data at √s=8 TeV. The inputs are well modelled within uncertainties, which builds confidence in the expected tagger performance.
AB - 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 <pT<<pT< 400 GeV in √s=8 TeV pp collisions with the ATLAS detector at the LHC. For Z-boson tagging efficiencies of ϵZ=90, 50, and 10%, one can achieve W+ -boson tagging rejection factors (1/ϵW+) 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 pT, 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−1 of data at √s=8 TeV. The inputs are well modelled within uncertainties, which builds confidence in the expected tagger performance.
U2 - 10.1140/epjc/s10052-016-4065-1
DO - 10.1140/epjc/s10052-016-4065-1
M3 - Journal article
VL - 76
JO - European Physical Journal C: Particles and Fields
JF - European Physical Journal C: Particles and Fields
SN - 1434-6044
IS - 5
M1 - 238
ER -