659 research outputs found
Dimension-six anomalous couplings in collision at the LHC
We have investigated the flavor changing top quark physics on the
dimension-six anomalous () couplings through the process
at the LHC by considering different
forward detector acceptances. In this paper, we have taken into account and
examine the effects of top quark decay. The sensitivity bounds on the anomalous
couplings and, branching ratio have been obtained at the
confidence level for the effective lagrangian approach. Besides, we have
investigated the effect of the anomalous couplings on single top quark spin
asymmetry.Comment: 24 pages, 8 figures. This version matches the published version in
Nucl.Phys.
Search for the Anomalous Interactions of Up-Type Heavy Quarks in Collision at the LHC
We investigate the anomalous interactions of heavy up-type quark t' in a
collision at the LHC. We have obtained 95% confidence
level(CL)limit of anomalous coupling by taking into account three
forward detector acceptances: ,, and
.Comment: 16 pages, 3 figures, 3 table
Probe of unparticles at the LHC in exclusive two lepton and two photon production via photon-photon fusion
The exclusive production pp->pXp is known to be one of the most clean
channels at the LHC. We investigate the potential of processes pp -> p l-l+ p
and pp-> p gamma gamma p to probe scalar and tensor unparticles by considering
three different forward detector acceptances; 0.0015<xi<0.15, 0.0015<xi<0.5 and
0.1<xi<0.5. We obtain 95% confidence level sensitivity limits on the unparticle
couplings for various integrated luminosities.Comment: 27 pages, 17 figure
Probe of the Anomalous Quartic Couplings with Beam Polarization at the CLIC
We have investigated the anomalous quartic couplings defined by the
dimension-8 operators in semileptonic decay channel of the
process for
unpolarized and polarized electron (positron) beam at the Compact Linear
Collider. We give the confidence level bounds on anomalous
, and
couplings for various values of the integrated
luminosities and center-of-mass energies. The best sensitivities obtained on
anomalous , and
couplings through the process
with beam
polarization at TeV and an integrated luminosity of
fb are GeV, GeV, GeV,
which show improvement over the current bounds.Comment: 8 pages, 7 figures and 8 tables, published versio
Anomalous couplings with beam polarization at the Compact Linear Collider
We study the anomalous couplings at the Compact Linear Collider
through the processes , and is the Weizsacker-Williams
photon). We give the 95\% confidence level limits for unpolarized and polarized
electron (positron) beam on the anomalous couplings for various values of the
integrated luminosities and center-of-mass energies. We show that the obtained
limits on the anomalous couplings through these processes can highly improve
the current experimental limits. In addition, our limits with beam polarization
are approximately two times better than the unpolarized case.Comment: Tables and references adde
The impact of excited neutrinos on process
We examine the effect of excited neutrinos on the annihilation of relic
neutrinos with ultra high energy cosmic neutrinos for the process. The contribution of the excited neutrinos to the
neutrino-photon decoupling temperature are calculated. We see that
photon-neutrino decoupling temperature can be significantly reduced below the
obtained value of the Standard Model with the impact of excited neutrinos.Comment: 11 pages, 3 figures, published versio
Search for invisible dark photon in scattering at future lepton colliders
For the first time, the production of a massive dark photon (DP) in the
scattering at the future lepton colliders ILC, CLIC, and CEPC is
examined. The invisible decay mode of the DP is addressed. We have studied both
the unpolarized scattering and the collision of the Compton backscattered
photons with the polarized electron. The missing energy distributions are
shown. We have considered the wide range 10 GeV -- 1000 GeV of the DP mass
. The excluded regions at the 95\% C.L. in the plane , where is the kinetic mixing parameter, are obtained.Comment: 24 pages, 10 figures; one equation and two references are adde
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