83 research outputs found
FCNC in left-right symmetric theories and constraints on the right-handed scale
We revise the limits on the FCNC higgses in manifestly left-right symmetric
theories. It is shown that the combination of the Kobayashi-Maskawa
CP-violation with the tree level higgs exchange gives very large
contribution to the CP-violating parameter. It leads to the new
strong constraint on the FCNC higgs mass, M>50- 100 TeV, enhanced by factor of
the order . Being addressed to the supersymmetric left-right
models, FCNC problem requires both right-handed scale and supersymmetric mass
parameters be heavier than 50 TeV for . The most relaxed case
corresponds to where right-handed scale can be of the
order of few TeV.Comment: 11 pages, latex, 3 figure
Simple supersymmetric solution to the strong CP problem
It is shown that the minimal supersymmetric left-right model can provide a
natural solution to the strong {\it CP} problem without the need for an axion,
nor any additional symmetries beyond supersymmetry and parity.Comment: Plain Latex. 10 pages, including two figures which are part of the
Latex file. Shortened version, to appear in Phys. Rev. Lett. 7
Supersymmetric Left-Right Model and Light Doubly Charged Higgs Bosons and Higgsinos
We point out that in a large class of supersymmetric left-right models with
automatic R-parity conservation there are a pair of light doubly charged Higgs
bosons and Higgsinos. Requiring the mass of these particles to satisfy the LEP
Z-width bound implies that mass must be above GeV.Comment: 9 pages; no figure
Solution to the Strong CP Problem: Supersymmetry with Parity
There is a natural solution to the strong CP problem in the Minimal
Supersymmetric Standard Model if it arises from a parity symmetric theory which
is spontaneously broken to MSSM at Planck, GUT or intermediate scales. The
strong CP phase is zero at the tree level and is not induced to two loops. The
SUSY phase problems are also solved. The universal soft SUSY breaking
parameters A, B, \mu, m_{1/2} are all automatically real and the only
additional CP violation effects of the low-energy MSSM are characterized by a
Hermitian squark mass matrix whose phases depend on the CKM phase. Cases with
non-universal boundary conditions are also considered.Comment: Typo in an equation corrected. Results unchanged. 8 pages, Late
Testing leptonic SU(2) horizontal symmetry using neutrino mixings
After some preliminary arguments suggesting that neutrino mixings with
inverted mass pattern may be easier to understand within the framework of a
local horizontal symmetry SU(2)_H acting on leptons, we construct a specific
extension of the minimal supersymmetric standard model that implements the idea
and analyze its predictions. We show that the horizontal symmetry leads to an
experimentally testable relation between the neutrino parameters U_{e3} and the
ratio of solar and atmospheric mass difference squared i.e. U^2_{e3} cos 2
theta_{odot} = (Delta m^2_{odot})/(2 Delta m^2_A) + O(U^4_{e3}, (m_e/m_mu)^2).
Taking the solar neutrino parameters inferred from present data at 99.7%
confidence level, the above relation leads to a lower bound on U_{e3} >= 0.08
and an allowed region in the U_{e3} and (Delta m^2_{odot})/(2 Delta m^2_A)
space which can be tested in proposed long baseline experiments.Comment: 11 pages, one figure; model made supersymmetric, final conclusions
unchanged, new references adde
Higgs sector and R-parity breaking couplings in models with broken U(1)_B-L gauge symmetry
Four different supersymmetric models based on SU(2)_L X U(1)_R X U(1)_B-L and
SU(2)_L X SU(2)_R X U(1)_B-L gauge symmetry groups are studied. U(1)_B-L
symmetry is broken spontaneously by a vacuum expectation value (VEV) of a
sneutrino field. The right-handed gauge bosons may obtain their mass solely by
sneutrino VEV. The physical charged lepton and neutrino are mixtures of
gauginos, higgsinos and lepton interaction eigenstates. Explicit formulae for
masses and mixings in the physical lepton fields are found. The spontaneous
symmetry breaking mechanism fixes the trilinear R-parity breaking couplings.
Only some special R-parity breaking trilinear couplings are allowed. There is a
potentially large trilinear lepton number breaking coupling - which is unique
to left-right models - that is proportional to the SU(2)_R gauge coupling g_R.
The couplings are parametrized by few mixing angles, making the spontaneous
R-parity breaking a natural ``unification framework'' for R-parity breaking
couplings in SUSYLR models.Comment: 19 pages, no figures, uses REVTeX. To be published in PR
Minimal Supersymmetric Left-Right Model
We construct the truly minimal left-right symmetric model by utilizing only
the fields dictated by supersymmetry and automatic R-parity conservation.
Allowing for non-renormalizable operators in the superpotential, we show that
parity can be spontaneously broken while preserving electromagnetic gauge
invariance. The scale of parity breakdown is predicted in the intermediate
region: , and R-parity remains exact. The theory
contains a number of charged and doubly charged Higgs scalars with a low mass
of order , accessible to experiment.Comment: 5 pages, Revtex, no figure
Reconciling Supersymmetry and Left-Right Symmetry
We construct the minimal supersymmetric left-right theory and show that at
the renormalizable level it requires the existence of an intermediate
breaking scale. The subsequent symmetry breaking down to MSSM automatically
preserves R-symmetry. Furthermore, unlike in the nonsupersymmetric version of
the theory, the see-saw mechanism takes its canonical form. The theory predicts
the existence of a triplet of Higgs scalars much lighter than the
breaking scale.Comment: 4 pages, revtex, no figure
Implications of supersymmetric models with natural R-parity conservation
In the minimal supersymmetric standard model, the conservation of R-parity is
phenomenologically desirable, but is ad hoc in the sense that it is not
required for the internal consistency of the theory. However, if B-L is gauged
at very high energies, R-parity will be conserved automatically and exactly,
provided only that all order parameters carry even integer values of 3(B-L). We
propose a minimal extension of the supersymmetric standard model in which
R-parity conservation arises naturally in this way. This approach predicts the
existence of a very weakly coupled, neutral chiral supermultiplet of particles
with electroweak-scale masses and lifetimes which may be cosmologically
interesting. Neutrino masses arise via an intermediate-scale seesaw mechanism,
and a solution to the problem is naturally incorporated. The apparent
unification of gauge couplings at high energies is shown to be preserved in
this approach. We also discuss a next-to-minimal extension, which predicts a
pair of electroweak-scale chiral supermultiplets with electric charge 2.Comment: 19 pages, plain TeX, no figure
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