Fourth Generation and Vector Like Quark (VLQ) models are extensions of the
Standard Model of particles physics. These models predict the existence of new
heavy quarks like heavy top quark t' with electric charge 2/3
and heavy bottom quark b' with electric charge -1/3. The t' and b' will
act the fourth generation quarks. In current work we present a search for a
pair production of a fourth generation quark, t' quark
and its antiparticle, followed by their decays to Z, W bosons
followed by decays to trilepton e-e-μ+ plus jets and missing
transverse energy in the final state according to the process . We
use Monte Carlo simulation techniques Pythia8, MadGraph5 and CalcHEP to
simulate this process at both the Large Hadron Collider at CERN (proton-proton
collisions) and the Fermilab Tevatron Collider (proton-antiproton collisions).
We assume that the t' quark is a narrow state that always
decay to a W and Z bosons plus jets. We
select 2 electrons + jets+ missing energy final states with one isolated μ with high transverse momentum. The three charged leptons plus
missing energy in the final state offer the best discovery potential at the
hadron colliders for new heavy top quark mass of 500 GeV. We study the possible
signals at both the LHC and the Tevatron of new quarks t' coupled
to the third generation quarks in the context of fourth generation and vector
like quark models under the assumption of a branching ratios BR(t'→Wb)=50% and BR(t'→Zt)=50%.
Heavy quark pair production gives interesting signals in final states with
three charged leptons plus missing energy. Finally, from our analysis the new
heavy fourth generation quark t' can be discovered at both the
Tevatron and the LHC with mass 500 GeV.
Cite this paper
Bakhet, N. , Khlopov, M. , Hussein, T. (2014) Search for Signatures of New Heavy Top Quark of the Fourth Generation at the Hadron Colliders. Open Journal of Microphysics
, 35-45. doi: 10.4236/ojm.2014.44006
 ATLAS Collaboration (2012) Observation of a New Particle in the Search for the Standard Model Higgs Boson with the ATLAS Detector at the LHC. Physics Letters B, 716, 1-29. http://dx.doi.org/10.1016/j.physletb.2012.08.020
 CMS Collaboration (2012) Observation of a New Boson at a Mass of 125 GeV with the CMS Experiment at the LHC. Physics Letters B, 716, 30-61. http://dx.doi.org/10.1016/j.physletb.2012.08.021
 Djouadi, A. and Lenz, A. (2012) Sealing the Fate of a Fourth Generation of Fermions. arXiv:1204.1252v2
 ATLAS Collaboration (2011) Update of the Combination of Higgs Boson Searches in pp Collisions at Sqrt(s) = 7 TeV with the ATLAS Experiment at the LHC ATLAS-CONF-2011-135, 2011.
 CMS Collaboration (2012) Combined Results of Searches for a Higgs Boson in the Context of the Standard Model and beyond Standard Models. CMS PAS HIG-12-008.
 Cetin, S.A., et al. (2011) Status of the Fourth Generation—A Brief Summary of B3SM-III Workshop in Four Parts. arXiv: 1112.2907 [hep-ex].
 Aguilar-Saavedra, J.A. JHEP 0911 (2009) Identifying top Partners at LHC. 030. http://dx.doi.org/10.1088/1126-6708/2009/11/030
 Abachi, S. et al. (D0 Collaboration) (1995) Observation of the Top Quark. Physical Review Letters, 74, 2632. http://dx.doi.org/10.1103/PhysRevLett.74.2632
 CMS Collaboration (2012) Search for Pair Produced Fourth-Generation Up-Type Quarks in pp Collisions at Sqrt(s) = 7 TeV with a Lepton in the Final State. CERN-PH-EP/2012-244.
 CMS Collaboration (2012) Search for Heavy, Top-Like Quark Pair Production in the Dilepton Final State in pp Collisions at Sqrt(s) = 7. Physics Letters B, 716, 103-121. http://dx.doi.org/10.1016/j.physletb.2012.07.059
 D0 Collaboration (2011) Search for a Fourth Generation t’ Quark in ppbar Collisions at Sqrt(s) =1.96 TeV. arXiv: 1104.4522v.1
 Kidonakis, N. (2006) Single Top Quark Production at the Fermilab Tevatron: Threshold Resummation and Finite-Order Soft Gluon Corrections. Physical Review D, 74, 114012. http://dx.doi.org/10.1103/PhysRevD.74.114012
 Campbell, J. and Ellis, R.K. (2002) Next-to-Leading Order Corrections to W + 2 Jet and Z + 2 Jet Production at Hadron Colliders. Physical Review D, 65,113007. http://dx.doi.org/10.1103/PhysRevD.65.113007
 Chatrchyan, S., et al. (CMS Collaboration) (2011) Measurement of the Production Cross Section in pp Collisions at 7 TeV in Lepton + Jets Events Using b-Quark Jet Identification. Physical Review D, 84, 092004. http://dx.doi.org/10.1103/PhysRevD.84.092004
 Kidonakis, N. (2009) Single Top Quark Production at the Fermilab Tevatron: Threshold Resummation and Finite-Order Soft Gluon Corrections. arXiv: 0909.0037.
 Alwall, J., et al. (2011) MadGraph 5: Going Beyond. Journal of High Energy Physics, 128. http://dx.doi.org/10.1007/JHEP06(2011)128
 Sjostrand, T. (2006) 026 PYTHIA 6.4 Physics and Manual. JHEP 05 026.
 Belyaev, A. (2012) CalcHEP 3.4 for Collider Physics within and beyond the Standard Model. arXiv:1207.6082