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

Journal Article (Journal Article)

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.

Full Text

Duke Authors

Cited Authors

  • Aaboud, M; Aad, G; Abbott, B; Abdinov, O; Abeloos, B; Abhayasinghe, DK; Abidi, SH; Abouzeid, OS; Abraham, NL; Abramowicz, H; Abreu, H; Abulaiti, Y; Acharya, BS; Adachi, S; Adamczyk, L; Adelman, J; Adersberger, M; Adiguzel, A; Adye, T; Affolder, AA; Afik, Y; Agheorghiesei, C; Aguilar-Saavedra, JA; Ahmadov, F; Aielli, G; Akatsuka, S; Åkesson, TPA; Akilli, E; Akimov, AV; Alberghi, GL; Albert, J; Albicocco, P; Alconada Verzini, MJ; Alderweireldt, S; Aleksa, M; Aleksandrov, IN; Alexa, C; Alexopoulos, T; Alhroob, M; Ali, B; Alimonti, G; Alison, J; Alkire, SP; Allaire, C; Allbrooke, BMM; Allen, BW; Allport, PP; Aloisio, A; Alonso, A; Alonso, F; Alpigiani, C; Alshehri, AA; Alstaty, MI; Alvarez Gonzalez, B; Álvarez Piqueras, D; Alviggi, MG; Amadio, BT; Amaral Coutinho, Y; Ambroz, L; Amelung, C; Amidei, D; Amor Dos Santos, SP; Amoroso, S; Amrouche, CS; Anastopoulos, C; Ancu, LS; Andari, N; Andeen, T; Anders, CF; Anders, JK; Anderson, KJ; Andreazza, A; Andrei, V; Anelli, CR; Angelidakis, S; Angelozzi, I; Angerami, A; Anisenkov, AV; Annovi, A; Antel, C; Anthony, MT; Antonelli, M; Antrim, DJA; Anulli, F; Aoki, M; Aparisi Pozo, JA; Aperio Bella, L; Arabidze, G; Araque, JP; Araujo Ferraz, V; Araujo Pereira, R; Arce, ATH; Ardell, RE; Arduh, FA; Arguin, JF; Argyropoulos, S; Armbruster, AJ; Armitage, LJ; Armstrong, A; Arnaez, O

Published Date

  • December 1, 2018

Published In

Volume / Issue

  • 98 / 11

Electronic International Standard Serial Number (EISSN)

  • 2470-0029

International Standard Serial Number (ISSN)

  • 2470-0010

Digital Object Identifier (DOI)

  • 10.1103/PhysRevD.98.112010

Citation Source

  • Scopus