Search for pair and single production of new heavy quarks that decay to a Z boson and a third-generation quark in pp collisions at (Formula presented.) TeV with the ATLAS detector

The ATLAS Collaboration

Research output: Contribution to journalArticle

53 Citations (Scopus)

Abstract

Abstract: A search is presented for the production of new heavy quarks that decay to a Z boson and a third-generation Standard Model quark. In the case of a new charge +2/3 quark (T ), the decay targeted is T → Zt, while the decay targeted for a new charge −1/3 quark (B) is B → Zb. The search is performed with a dataset corresponding to 20.3 fb−1 of pp collisions at (Formula presented.) TeV recorded in 2012 with the ATLAS detector at the CERN Large Hadron Collider. Selected events contain a high transverse momentum Z boson candidate reconstructed from a pair of oppositely charged same-flavor leptons (electrons or muons), and are analyzed in two channels defined by the absence or presence of a third lepton. Hadronic jets, in particular those with properties consistent with the decay of a b-hadron, are also required to be present in selected events. Different requirements are made on the jet activity in the event in order to enhance the sensitivity to either heavy quark pair production mediated by the strong interaction, or single production mediated by the electroweak interaction. No significant excess of events above the Standard Model expectation is observed, and lower limits are derived on the mass of vector-like T and B quarks under various branching ratio hypotheses, as well as upper limits on the magnitude of electroweak coupling parameters.

Original languageEnglish (US)
Article number104
JournalJournal of High Energy Physics
Volume2014
Issue number11
DOIs
StatePublished - 2014

Fingerprint

pair production
bosons
quarks
collisions
detectors
decay
leptons
transverse momentum
muons
requirements
sensitivity
electrons

Keywords

  • Hadron-Hadron Scattering

ASJC Scopus subject areas

  • Nuclear and High Energy Physics

Cite this

@article{eaea85bbd42f4c79ae6b3af5ad16662a,
title = "Search for pair and single production of new heavy quarks that decay to a Z boson and a third-generation quark in pp collisions at (Formula presented.) TeV with the ATLAS detector",
abstract = "Abstract: A search is presented for the production of new heavy quarks that decay to a Z boson and a third-generation Standard Model quark. In the case of a new charge +2/3 quark (T ), the decay targeted is T → Zt, while the decay targeted for a new charge −1/3 quark (B) is B → Zb. The search is performed with a dataset corresponding to 20.3 fb−1 of pp collisions at (Formula presented.) TeV recorded in 2012 with the ATLAS detector at the CERN Large Hadron Collider. Selected events contain a high transverse momentum Z boson candidate reconstructed from a pair of oppositely charged same-flavor leptons (electrons or muons), and are analyzed in two channels defined by the absence or presence of a third lepton. Hadronic jets, in particular those with properties consistent with the decay of a b-hadron, are also required to be present in selected events. Different requirements are made on the jet activity in the event in order to enhance the sensitivity to either heavy quark pair production mediated by the strong interaction, or single production mediated by the electroweak interaction. No significant excess of events above the Standard Model expectation is observed, and lower limits are derived on the mass of vector-like T and B quarks under various branching ratio hypotheses, as well as upper limits on the magnitude of electroweak coupling parameters.",
keywords = "Hadron-Hadron Scattering",
author = "{The ATLAS Collaboration} and G. Aad and B. Abbott and J. Abdallah and {Abdel Khalek}, S. and O. Abdinov and R. Aben and B. Abi 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 T. Agatonovic-Jovin and Aguilar-Saavedra, {J. A.} and M. Agustoni and Ahlen, {S. P.} and F. Ahmadov and G. Aielli and H. Akerstedt and {\AA}kesson, {T. P A} and G. Akimoto 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 G. Alexandre and T. Alexopoulos and M. Alhroob and G. Alimonti and L. Alio and J. Alison and Allbrooke, {B. M M} and Allison, {L. J.} and Cheu, {Elliott C} and Johns, {Kenneth A} and Rutherfoord, {John P} and Shupe, {Michael A} and Varnes, {Erich W}",
year = "2014",
doi = "10.1007/JHEP11(2014)104",
language = "English (US)",
volume = "2014",
journal = "Journal of High Energy Physics",
issn = "1126-6708",
publisher = "Springer Verlag",
number = "11",

}

TY - JOUR

T1 - Search for pair and single production of new heavy quarks that decay to a Z boson and a third-generation quark in pp collisions at (Formula presented.) TeV with the ATLAS detector

AU - The ATLAS Collaboration

AU - Aad, G.

AU - Abbott, B.

AU - Abdallah, J.

AU - Abdel Khalek, S.

AU - Abdinov, O.

AU - Aben, R.

AU - Abi, B.

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 - Agatonovic-Jovin, T.

AU - Aguilar-Saavedra, J. A.

AU - Agustoni, M.

AU - Ahlen, S. P.

AU - Ahmadov, F.

AU - Aielli, G.

AU - Akerstedt, H.

AU - Åkesson, T. P A

AU - Akimoto, G.

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 - Alexandre, G.

AU - Alexopoulos, T.

AU - Alhroob, M.

AU - Alimonti, G.

AU - Alio, L.

AU - Alison, J.

AU - Allbrooke, B. M M

AU - Allison, L. J.

AU - Cheu, Elliott C

AU - Johns, Kenneth A

AU - Rutherfoord, John P

AU - Shupe, Michael A

AU - Varnes, Erich W

PY - 2014

Y1 - 2014

N2 - Abstract: A search is presented for the production of new heavy quarks that decay to a Z boson and a third-generation Standard Model quark. In the case of a new charge +2/3 quark (T ), the decay targeted is T → Zt, while the decay targeted for a new charge −1/3 quark (B) is B → Zb. The search is performed with a dataset corresponding to 20.3 fb−1 of pp collisions at (Formula presented.) TeV recorded in 2012 with the ATLAS detector at the CERN Large Hadron Collider. Selected events contain a high transverse momentum Z boson candidate reconstructed from a pair of oppositely charged same-flavor leptons (electrons or muons), and are analyzed in two channels defined by the absence or presence of a third lepton. Hadronic jets, in particular those with properties consistent with the decay of a b-hadron, are also required to be present in selected events. Different requirements are made on the jet activity in the event in order to enhance the sensitivity to either heavy quark pair production mediated by the strong interaction, or single production mediated by the electroweak interaction. No significant excess of events above the Standard Model expectation is observed, and lower limits are derived on the mass of vector-like T and B quarks under various branching ratio hypotheses, as well as upper limits on the magnitude of electroweak coupling parameters.

AB - Abstract: A search is presented for the production of new heavy quarks that decay to a Z boson and a third-generation Standard Model quark. In the case of a new charge +2/3 quark (T ), the decay targeted is T → Zt, while the decay targeted for a new charge −1/3 quark (B) is B → Zb. The search is performed with a dataset corresponding to 20.3 fb−1 of pp collisions at (Formula presented.) TeV recorded in 2012 with the ATLAS detector at the CERN Large Hadron Collider. Selected events contain a high transverse momentum Z boson candidate reconstructed from a pair of oppositely charged same-flavor leptons (electrons or muons), and are analyzed in two channels defined by the absence or presence of a third lepton. Hadronic jets, in particular those with properties consistent with the decay of a b-hadron, are also required to be present in selected events. Different requirements are made on the jet activity in the event in order to enhance the sensitivity to either heavy quark pair production mediated by the strong interaction, or single production mediated by the electroweak interaction. No significant excess of events above the Standard Model expectation is observed, and lower limits are derived on the mass of vector-like T and B quarks under various branching ratio hypotheses, as well as upper limits on the magnitude of electroweak coupling parameters.

KW - Hadron-Hadron Scattering

UR - http://www.scopus.com/inward/record.url?scp=84925620206&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84925620206&partnerID=8YFLogxK

U2 - 10.1007/JHEP11(2014)104

DO - 10.1007/JHEP11(2014)104

M3 - Article

AN - SCOPUS:84925620206

VL - 2014

JO - Journal of High Energy Physics

JF - Journal of High Energy Physics

SN - 1126-6708

IS - 11

M1 - 104

ER -