105 research outputs found
Up Sector of Minimal Flavor Violation: Top Quark Properties and Direct D meson CP violation
Minimal Flavor Violation in the up-type quark sector leads to particularly
interesting phenomenology due to the interplay of flavor physics in the charm
sector and collider physics from flavor changing processes in the top sector.
We study the most general operators that can affect top quark properties and
meson decays in this scenario, concentrating on two CP violating operators
for detailed studies. The consequences of these effective operators on charm
and top flavor changing processes are generically small, but can be enhanced if
there exists a light flavor mediator that is a Standard Model gauge singlet
scalar and transforms under the flavor symmetry group. This flavor mediator can
satisfy the current experimental bounds with a mass as low as tens of GeV and
explain observed -meson direct CP violation. Additionally, the model
predicts a non-trivial branching fraction for a top quark decay that would
mimic a dijet resonance.Comment: 27 pages, 7 figure
Ghosts- and Tachyon-Free Regions of the Randall-Sundrum Model Parameter Space
Model building within the Randall-Sundrum (RS) framework generally involves
placing the Standard Model fields in the bulk. Such fields may possess non-zero
values for their associated brane-localized kinetic terms (BLKTs) in addition
to possible bulk mass parameters. In this paper we clearly identify the regions
of the RS model parameter space where the presence of bulk mass terms and BLKTs
yield a setup which is free from both ghost and tachyon instabilities. Such
physically acceptable parameter space regions can then be used to construct
realistic and phenomenologically viable RS models.Comment: Latex, 30 pages, 2 figure
Probing Top-Quark Couplings at Lepton and Photon Colliders
The ability of high energy lepton and photon colliders to probe the gauge
couplings of the top-quark is summarized.Comment: 10 pages, LaTex, to appear in the Proceedings of the 2nd
International Workshop on e-e- Interactions at TeV Energies, Santa Cruz, CA,
22-24 September 199
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