PT Journal
AU ATLAS Collaboration (Aaboud, Mea
   Alvarez Piqueras, D
   Bailey, AJ
   Barranco Navarro, L
   Cabrera Urban, S
   Castillo, FL
   Castillo Gimenez, V
   Cerda Alberich, L
   Costa, MJ
   Escobar, C
   Estrada Pastor, O
   Ferrer, A
   Fiorini, L
   Fuster, J
   Garcia, C
   Garcia Navarro, JE
   Gonzalez de la Hoz, S
   Higon-Rodriguez, E
   Jimenez Pena, J
   Lacasta, C
   Lozano Bahilo, JJ
   Madaffari, D
   Mamuzic, J
   Marti-Garcia, S
   Melini, D
   Miñano, M
   Mitsou, VA
   Pedraza Lopez, S
   Rodriguez Bosca, S
   Rodriguez Rodriguez, D
   Salt, J
   Soldevila, U
   Sanchez, J
   Valero, A
   Valls Ferrer, JA
   Vos, M
TI Search for pair production of heavy vectorlike quarks decaying into hadronic final states in pp collisions at root s=13 TeV with the ATLAS detector
SO Physical Review D
JI Phys. Rev. D
PY 2018
BP 092005
EP 36pp
VL 98
IS 9
DI 10.1103/PhysRevD.98.092005
LA English
AB A search is presented for the pair production of heavy vectorlike quarks, T (T) over bar or B (B) over bar, that decay into final states with jets and no reconstructed leptons. Jets in the final state are classified using a deep neural network as arising from hadronically decaying W/Z bosons, Higgs bosons, top quarks, or background. The analysis uses data from the ATLAS experiment corresponding to 36.1 fb(-1) of proton-proton collisions with a center-of-mass energy of root s = 13 TeV delivered by the Large Hadron Collider in 2015 and 2016. No significant deviation from the Standard Model expectation is observed. Results are interpreted assuming the vectorlike quarks decay into a Standard Model boson and a third-generation-quark, T -> Wb, Ht, Zt or B -> Wt, Hb, Zb, for a variety of branching ratios. At 95% confidence level, the observed (expected) lower limit on the vectorlike B-quark mass for a weak-isospin doublet (B, Y) is 950 (890) GeV, and the lower limits on the masses for the pure decays B -> Hb and T -> Ht, where these results are strongest, arc 1010 (970) GeV and 1010 (1010) GeV, respectively.
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