TITLE:
Search for Signatures of New Heavy Top Quark of the Fourth Generation at the Hadron Colliders
AUTHORS:
Nady Bakhet, Maxim Yu Khlopov, Tarek Hussein
KEYWORDS:
LHC, Tevatron, Fourth Generation Model, Heavy Top, Monte Carlo Simulation
JOURNAL NAME:
Open Journal of Microphysics,
Vol.4 No.4,
October
24,
2014
ABSTRACT: The
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.