61 research outputs found
Discovery and Identification of W' Bosons at e+e- Colliders
We report on studies of the sensitivity to extra gauge bosons of the
reactions e^+ e^- -> nu nubar gamma and e gamma -> nu q + X to extract
discovery limits for W' 's. The discovery potential for a W' is, for some
models, comparable to that of the LHC. These processes may be also useful for
determining W' and Z' couplings to fermions which would complement measurements
made at the Large Hadron Collider.Comment: 3 pages, 2 postscript figures, Presented at the DPF2000 Conference,
August 9-12, 2000, The Ohio State University, Columbus, Ohi
Report of the Subgroup on Alternative Models and New Ideas
We summarize some of the work done by the P3 subgroup on Alternative Models
and New Ideas. The working group covered a broad range of topics including a
constrained Standard Model from an extra dimension, a discussion of recent
ideas addressing the strong CP problem, searches for doubly charged higgs
bosons in e gamma collisions, and an update on discovery limits for extra
neutral gauge bosons at hadron colliders. The breadth of topics reflects the
many ideas and approaches to physics beyond the Standard Model.Comment: 10 pages, 5 figures. Contributed to the APS/DPF/DPB Summer Study on
the Future of Particle Physics (Snowmass 2001), Snowmass, Colorado, 30 Jun -
21 Jul 200
New Solution for Neutrino Masses and Leptogenesis in Adjoint SU(5)
We investigate baryogenesis via leptogenesis and generation of neutrino
masses and mixings through the Type I plus Type III seesaw plus an one-loop
mechanism in the context of Renormalizable Adjoint SU(5) theory. One light
neutrino remains massless, because the contributions of three heavy Majorana
fermions \rho_0, \rho_3 and \rho_8 to the neutrino mass matrix are not linearly
independent. However none of these heavy fermions is decoupled from the
generation of neutrino masses. This opens a new range in parameter space for
successful leptogenesis, in particular, allows for inverted hierarchy of the
neutrino masses.Comment: 16 pages, 4 figures; references added and typos fixe
Extracting W Boson Couplings from the Production of Four Leptons
We consider the processes , including all possible charged lepton combinations, with
regard to measuring parameters characterizing the boson. We calculate at
what level these processes can be used to measure anamolous triple-boson
vertice coupling parameters for the cases of colliders at 500
and 1 center of mass energies.Comment: 13 pages,OCIP/C-93-
Study of non-minimal SUSY SU(5) model with realistic fermion sectors
We study a supersymmetric SU(5) model with the extra Higgs multiplets of
45+\bar 45. The unification of the gauge couplings, the fermion masses and the
proton lifetime are discussed in details. The dimension-five operators mediated
by different colored Higgs sector can be destructive with each other. This
effect serves a way of solving the longevity of proton. We analytically analyze
this destructive effect in a special limit where the mixing between the 5- and
45-plets is small. Although the theory does not hold in this special limit, it
is a revelatory starting point. We can relax this limit and retain the
destructive effect. In a generalized parameter space, this model is in accord
with experimental results
Charged Lepton Flavour Violation from Massive Neutrinos in Z Decays
Present evidences for neutrino masses and lepton flavour mixings allow to
predict, in the Standard Model with light neutrinos, branching rates for the
decays Z --> e mu, mu tau, e tau of less than 10^{-54}, while present
experimental exclusion limits from LEP 1 are of order 10^{-5}. The GigaZ option
of the TESLA Linear Collider project will extend the sensitivity down to about
10^{-8}. We study in a systematic way some minimal extensions of the Standard
Model and show that GigaZ might well be sensitive to the rates predicted from
these scenarios.Comment: 24 pages, 4 figures, LaTeX, uses axodraw.st
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