148 research outputs found
Analyzing the anomalous dipole moment type couplings of heavy quarks with FCNC interactions at the CLIC
In this study we examine both anomalous magnetic and dipole moment type
couplings of a heavy quark via its single production with subsequent dominant
Standard Model decay modes at the Compact Linear Collider (CLIC). The signal
and background cross sections are analyzed for heavy quark masses 600 and 700
GeV. We make the analysis to delimitate these couplings as well as to find the
attainable integrated luminosities or 3 observation limit.Comment: 13 pages, 10 figure
Single and pair production of heavy leptons in model
We investigate the single and pair production of new heavy leptons via string
inspired model at future linear colliders. Signal and corresponding
backgrounds for these leptons are studied. We have found that single production
of heavy leptons is more relevant than that of pair production, as expected.
For a maximal mixing value of 0.1, the upper mass limits of 2750 GeV in the
single case and 1250 GeV in the pair production case are obtained at
TeV collider option.Comment: 14 pages, 10 figure
Anomalous single production of fourth family up type quark associated with neutral gauge bosons at the LHC
From the present limits on the masses and mixings of fourth family quarks,
they are expected to have mass larger than the top quark and allow a large
range of mixing of the third family. They could also have different dynamics
than the quarks of three families of the Standard Model. The single production
of the fourth family up type quark t' has been studied via anomalous production
process pp-> t'VX (where V=g,Z,\gamma) at the LHC with the center of mass
energy of 7 and 14 TeV. The signatures of such process are discussed within
both the SM decay modes and anomalous decay modes of t' quarks. The sensitivity
to anomalous coupling kappa/Lambda=0.004 TeV^(-1) can be reached at sqrt(s)=14
TeV and L_(int)=100 pb^(-1).Comment: 15 pages, 9 figure
Search for Top Quark FCNC Couplings in Z' Models at the LHC and CLIC
The top quark is the heaviest particle to date discovered, with a mass close
to the electroweak symmetry breaking scale. It is expected that the top quark
would be sensitive to the new physics at the TeV scale. One of the most
important aspects of the top quark physics can be the investigation of the
possible anomalous couplings. Here, we study the top quark flavor changing
neutral current (FCNC) couplings via the extra gauge boson Z' at the Large
Hadron Collider (LHC) and the Compact Linear Collider (CLIC) energies. We
calculate the total cross sections for the signal and the corresponding
Standard Model (SM) background processes. For an FCNC mixing parameter x=0.2
and the sequential Z' mass of 1 TeV, we find the single top quark FCNC
production cross sections 0.38(1.76) fb at the LHC with sqrt{s_{pp}}=7(14) TeV,
respectively. For the resonance production of sequential Z' boson and decays to
single top quark at the Compact Linear Collider (CLIC) energies, including the
initial state radiation and beamstrahlung effects, we find the cross section
27.96(0.91) fb at sqrt{s_{e^{+}e^{-}}}=1(3) TeV, respectively. We make the
analysis to investigate the parameter space (mixing-mass) through various Z'
models. It is shown that the results benefit from the flavor tagging.Comment: 20 pages, 17 figures, 6 table
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