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Search for pair and single production of vectorlike quarks in final states with at least one Z boson decaying into a pair of electrons or muons in pp collision data collected with the ATLAS detector at s =13 TeV

, ; Aaboud, M; Åkesson, Torsten LU ; Bocchetta, Simona LU ; Corrigan, Eric LU ; Doglioni, Caterina LU ; Gregersen, Kristian LU ; Brottmann Hansen, Eva LU ; Hedberg, Vincent LU and Jarlskog, Göran LU , et al. (2018) In Physical Review D 98(11).
Abstract
A search for vectorlike quarks is presented, which targets their decay into a Z boson and a third-generation Standard Model quark. In the case of a vectorlike quark T (B) with charge +2/3e (-1/3e), the decay searched for is T→Zt (B→Zb). Data for this analysis were taken during 2015 and 2016 with the ATLAS detector at the Large Hadron Collider and correspond to an integrated luminosity of 36.1 fb-1 of pp collisions at s=13 TeV. The final state used is characterized by the presence of b-tagged jets, as well as a Z boson with high transverse momentum, which is reconstructed from a pair of opposite-sign same-flavor leptons. Pair and single production of vectorlike quarks are both taken into account and are each searched for using optimized... (More)
A search for vectorlike quarks is presented, which targets their decay into a Z boson and a third-generation Standard Model quark. In the case of a vectorlike quark T (B) with charge +2/3e (-1/3e), the decay searched for is T→Zt (B→Zb). Data for this analysis were taken during 2015 and 2016 with the ATLAS detector at the Large Hadron Collider and correspond to an integrated luminosity of 36.1 fb-1 of pp collisions at s=13 TeV. The final state used is characterized by the presence of b-tagged jets, as well as a Z boson with high transverse momentum, which is reconstructed from a pair of opposite-sign same-flavor leptons. Pair and single production of vectorlike quarks are both taken into account and are each searched for using optimized dileptonic exclusive and trileptonic inclusive event selections. In these selections, the high scalar sum of jet transverse momenta, the presence of high-transverse-momentum large-radius jets, as well as - in the case of the single-production selections - the presence of forward jets are used. No significant excess over the background-only hypothesis is found and exclusion limits at 95% confidence level allow masses of vectorlike quarks of mT>1030 GeV (mT>1210 GeV) and mB>1010 GeV (mB>1140 GeV) in the singlet (doublet) model. In the case of 100% branching ratio for T→Zt (B→Zb), the limits are mT>1340 GeV (mB>1220 GeV). Limits at 95% confidence level are also set on the coupling to Standard Model quarks for given vectorlike quark masses. © 2018 CERN. (Less)
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Physical Review D
volume
98
issue
11
publisher
American Physical Society
external identifiers
  • scopus:85059482289
ISSN
1550-2368
DOI
10.1103/PhysRevD.98.112010
language
English
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yes
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be8c9c85-7d27-445a-8103-23b262993fb9
date added to LUP
2019-01-21 10:37:55
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2019-05-21 04:17:39
@article{be8c9c85-7d27-445a-8103-23b262993fb9,
  abstract     = {A search for vectorlike quarks is presented, which targets their decay into a Z boson and a third-generation Standard Model quark. In the case of a vectorlike quark T (B) with charge +2/3e (-1/3e), the decay searched for is T→Zt (B→Zb). Data for this analysis were taken during 2015 and 2016 with the ATLAS detector at the Large Hadron Collider and correspond to an integrated luminosity of 36.1 fb-1 of pp collisions at s=13 TeV. The final state used is characterized by the presence of b-tagged jets, as well as a Z boson with high transverse momentum, which is reconstructed from a pair of opposite-sign same-flavor leptons. Pair and single production of vectorlike quarks are both taken into account and are each searched for using optimized dileptonic exclusive and trileptonic inclusive event selections. In these selections, the high scalar sum of jet transverse momenta, the presence of high-transverse-momentum large-radius jets, as well as - in the case of the single-production selections - the presence of forward jets are used. No significant excess over the background-only hypothesis is found and exclusion limits at 95% confidence level allow masses of vectorlike quarks of mT>1030 GeV (mT>1210 GeV) and mB>1010 GeV (mB>1140 GeV) in the singlet (doublet) model. In the case of 100% branching ratio for T→Zt (B→Zb), the limits are mT>1340 GeV (mB>1220 GeV). Limits at 95% confidence level are also set on the coupling to Standard Model quarks for given vectorlike quark masses. © 2018 CERN.},
  articleno    = {112010},
  author       = {,  and Aaboud, M and Åkesson, Torsten and Bocchetta, Simona and Corrigan, Eric and Doglioni, Caterina and Gregersen, Kristian and Brottmann Hansen, Eva and Hedberg, Vincent and Jarlskog, Göran and Kalderon, Charles and Kellermann, Edgar and Konya, Balazs and Lytken, Else and Mankinen, Katja and Mjörnmark, Ulf and Poettgen, R. and Poulsen, Trine and Smirnova, Oxana and Zwalinski, L.},
  issn         = {1550-2368},
  language     = {eng},
  number       = {11},
  publisher    = {American Physical Society},
  series       = {Physical Review D},
  title        = {Search for pair and single production of vectorlike quarks in final states with at least one Z boson decaying into a pair of electrons or muons in pp collision data collected with the ATLAS detector at s =13 TeV},
  url          = {http://dx.doi.org/10.1103/PhysRevD.98.112010},
  volume       = {98},
  year         = {2018},
}