248 research outputs found
Probing Form Factors in Top Quark Pair Production at Colliders
We describe how to probe new physics through large CP violation effects and
non--standard Z-t-t couplings via the scattering process e^-e^+ -> t tbar.
[Talk presented at the Workshop on Physics and Experiments with Linear
Colliders, Waikoloa, Hawaii, 26-30 April 1993.]Comment: 4 pages, TeXsis, MSUTH 93/0
Production of Two Photons and a Jet Through Gluon Fusion
We have computed the cross-section and distributions for the production of two photons and a jet via the process . In the Standard Model, this process occurs at the one-loop level through pentagon and box diagrams. We show that at the LHC this is a significant mechanism for the production of the two photons and a jet. This process is also an important background to the Higgs boson production, when the Higgs boson decays into two photons. We also explorethis process at the Tevatron
Z boson transverse momentum spectrum from the lepton angular distributions
In view of recent discussions concerning the possibly limiting energy
resolution systematics on the measurement of the Z boson transverse momentum
distribution at hadron colliders, we propose a novel measurement method based
on the angular distributions of the decay leptons. We also introduce a
phenomenological parametrization of the transverse momentum distribution that
adapts well to all currently available predictions, a useful tool to quantify
their differences.Comment: 12 pages, 6 figure
Studying Anomalous and Couplings with Polarized Collisions
We calculate tree-level cross-sections for and
production in proton-antiproton collisions, with one decaying to leptons,
with anomalous electroweak triple-boson coupling parameters and
. We compare the unpolarized cross-sections to those for a polarized
proton beam, to study how a polarized proton beam would improve experimental
tests of anomalous couplings.Comment: 36 pages, 14 postscript figure
Tracing CP violation in the production of top quark pairs by multiple TeV proton-proton collisions
We investigate the possibilities of searching for non-standard CP violation
in at multiple TeV collision energies. A general kinematic
analysis of the underlying partonic production processes and
in terms of their density matrices is given. We evaluate
the CP-violating parts of these matrices in two-Higgs doublet extensions of the
standard model (SM) and give results for CP asymmetries at the parton level. We
show that these asymmetries can be traced by measuring suitable observables
constructed from energies and momenta of the decay products of and . We find CP-violating effects to be of the order of and show that
possible contaminations induced by SM interactions are savely below the
expected signals.Comment: 24 pages, SLAC-PUB-6403, PITHA 93/43, 9 Figs. available upon request.
Written in LaTe
A Probe of New Physics in Top Quark Pair Production at Colliders
We describe how to probe new physics through examination of the form factors
describing the Ztt couplings via the scattering process e^-e^+->t+tbar. We
focus on experimental methods on how the top quark momentum can be determined
and show how this can be applied to select polarized samples of
pairs through the angular correlations in the final state leptons. We also
study the dependence on the energy and luminosity of an \ee\ collider to probe
a CP violating asymmetry at the level.}Comment: 24 pages in TeXsis (figures available upon request) (revised July
1993
- …