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

The ATLAS collaboration

doi:10.1140/epjc/s10052-016-4065-1

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

The ATLAS collaboration

Aix-Marseille Université
University of Oklahoma
Academia Sinica - Institute of Physics
Azerbaijan National Academy of Sciences
University of Amsterdam
Michigan State University
University of Toronto
Tel Aviv University
Technion-Israel Institute of Technology
University of Oregon
Stockholm University
Oskar Klein Centre
National Institute for Nuclear Physics
Abdus Salam International Centre for Theoretical Physics
King's College London
AGH University of Krakow
Brookhaven National Laboratory
Northern Illinois University
Ludwig Maximilian University of Munich
Rutherford Appleton Laboratory
University of Liverpool
University of Belgrade
University of Göttingen
Laboratório de Instrumentação e Física Experimental de Partículas
University of Granada
Boston University
Joint Institute for Nuclear Research
University of Rome Tor Vergata
Lund University
P.N. Lebedev Physical Institute of the Russian Academy of Sciences
University of Bologna
University of Victoria BC
Université Grenoble Alpes
Instituto de Física La Plata
CERN
Horia Hulubei National Institute of Physics and Nuclear Engineering
National Technical University of Athens
The University of Chicago
Columbia University
University of Sussex

Research output: Contribution to journal › Article › peer-review

11 Scopus citations

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^′→ WZ for bosons in the transverse momentum range 200 GeV < _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.

Original language	English
Article number	238
Journal	European Physical Journal C
Volume	76
Issue number	5
DOIs	https://doi.org/10.1140/epjc/s10052-016-4065-1
State	Published - May 1 2016

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@article{13d0fc0b6c044592bea0c465b8a15afc,

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

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′→ WZ for bosons in the transverse momentum range 200 GeV < 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.",

author = "\{The ATLAS collaboration\} and G. Aad and B. Abbott and J. Abdallah and O. Abdinov and R. Aben and M. Abolins and AbouZeid, \{O. S.\} and H. Abramowicz and H. Abreu and R. Abreu and Y. Abulaiti and Acharya, \{B. S.\} and L. Adamczyk and Adams, \{D. L.\} and J. Adelman and S. Adomeit and T. Adye and Affolder, \{A. A.\} and T. Agatonovic-Jovin and J. Agricola and Aguilar-Saavedra, \{J. A.\} and Ahlen, \{S. P.\} and F. Ahmadov and G. Aielli and H. Akerstedt and {\AA}kesson, \{T. P.A.\} and Akimov, \{A. V.\} and Alberghi, \{G. L.\} and J. Albert and S. Albrand and \{Alconada Verzini\}, \{M. J.\} and M. Aleksa and Aleksandrov, \{I. N.\} and C. Alexa and G. Alexander and T. Alexopoulos and M. Alhroob and G. Alimonti and L. Alio and J. Alison and Alkire, \{S. P.\} and Allbrooke, \{B. M.M.\} and Allport, \{P. P.\} and H. Arnold and \{Da Via\}, C. and V. Dao and J. Hobbs and J. Jia and G. Piacquadio and D. Tsybychev",

note = "Publisher Copyright: {\textcopyright} 2016, CERN for the benefit of the ATLAS collaboration.",

year = "2016",

month = may,

day = "1",

doi = "10.1140/epjc/s10052-016-4065-1",

language = "English",

volume = "76",

journal = "European Physical Journal C",

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T1 - A new method to distinguish hadronically decaying boosted Z bosons from W bosons using the ATLAS detector

AU - The ATLAS collaboration

AU - Aad, G.

AU - Abbott, B.

AU - Abdallah, J.

AU - Abdinov, O.

AU - Aben, R.

AU - Abolins, M.

AU - AbouZeid, O. S.

AU - Abramowicz, H.

AU - Abreu, H.

AU - Abreu, R.

AU - Abulaiti, Y.

AU - Acharya, B. S.

AU - Adamczyk, L.

AU - Adams, D. L.

AU - Adelman, J.

AU - Adomeit, S.

AU - Adye, T.

AU - Affolder, A. A.

AU - Agatonovic-Jovin, T.

AU - Agricola, J.

AU - Aguilar-Saavedra, J. A.

AU - Ahlen, S. P.

AU - Ahmadov, F.

AU - Aielli, G.

AU - Akerstedt, H.

AU - Åkesson, T. P.A.

AU - Akimov, A. V.

AU - Alberghi, G. L.

AU - Albert, J.

AU - Albrand, S.

AU - Alconada Verzini, M. J.

AU - Aleksa, M.

AU - Aleksandrov, I. N.

AU - Alexa, C.

AU - Alexander, G.

AU - Alexopoulos, T.

AU - Alhroob, M.

AU - Alimonti, G.

AU - Alio, L.

AU - Alison, J.

AU - Alkire, S. P.

AU - Allbrooke, B. M.M.

AU - Allport, P. P.

AU - Arnold, H.

AU - Da Via, C.

AU - Dao, V.

AU - Hobbs, J.

AU - Jia, J.

AU - Piacquadio, G.

AU - Tsybychev, D.

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< 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< 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.

UR - https://www.scopus.com/pages/publications/84964889939

U2 - 10.1140/epjc/s10052-016-4065-1

DO - 10.1140/epjc/s10052-016-4065-1

M3 - Article

AN - SCOPUS:84964889939

SN - 1434-6044

VL - 76

JO - European Physical Journal C

JF - European Physical Journal C

IS - 5

M1 - 238

ER -

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

Abstract

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