53 research outputs found
Neutral Higgs sector of the next-to-minimal supersymmetric standard model with explicit CP violation
The neutral Higgs sector of the next-to-minimal supersymmetric standard model
(NMSSM) with explicit CP violation is investigated at the 1-loop level, using
the effective potential method; not only the loops involving the third
generation of quarks and scalar quarks, but also the loops involving boson,
charged Higgs boson, and chargino are taken into account. It is found that for
some parameter values of the NMSSM the contributions from the boson,
charged Higgs boson, and chargino loops may modify the masses of the neutral
Higgs bosons and the mixings among them significantly, depending on the CP
phase. In collisions, the prospects for discovering neutral Higgs
bosons are investigated within the context of the NMSSM with explicit CP
violation when the dominant component of the lightest neutral Higgs boson is
the Higgs singlet field of the NMSSM.Comment: Latex, 23 pages, 6 figure
Charged Higgs boson in the next-to-minimal supersymmetric standard model with explicit CP violation
The phenomenology of the explicit CP violation in the Higgs sector of the
next-to-minimal supersymmetric standard model (NMSSM) is investigated, with
emphasis on the charged Higgs boson. The radiative corrections due to both
quarks and scalar-quarks of the third generation are taken into account, and
the negative result of the search for the Higgs bosons at CERN LEP2, with the
discovery limit of 0.1 pb, is imposed as a constraint. It is found that there
are parameter regions of the NMSSM where the lightest neutral Higgs boson may
even be massless, without being detected at LEP2. This implies that the LEP2
data do not contradict the existence of a massless neutral Higgs boson in the
NMSSM. For the charged Higgs boson, the radiative corrections to its mass may
be negative in some parameter regions of the NMSSM. The phenomenological lower
bound on the radiatively corrected mass of the charged Higgs boson is increased
as the CP violation becomes maximal, i.e., as the CP violating phase becomes
. At the maximal CP violation, its lower bound is about 110 GeV for 5
40. The vacuum expectation value (VEV) of the
neutral Higgs singlet is shown to be no smaller than 16 GeV for any parameter
values of the NMSSM with explicit CP violation. This value of the lower limit
is found to increase up to about 45 GeV as the ratio () of the VEVs
of the two Higgs doublets decreases to smaller values ( 2). The discovery
limit of the Higgs boson search at LEP2 is found to cover about a half of the
kinematically allowed part of the whole parameter space of the NMSSM, and the
portion is roughly stable against the CP violating phase.Comment: Latex, 24 pages, 6 figure
Possibility of spontaneous CP violation in the nonminimal supersymmetric standard model with two neutral Higgs singlets
A supersymmetric standard model with two Higgs doublets and two Higgs
singlets is investigated if it can accommodate the possibility of spontaneous
CP violation. Assuming the degeneracy of the scalar quark masses of the third
generation, we find that spontaneous CP violation in the Higgs sector is viable
in our model. In the case of spontaneous CP violation, the masses of the
lightest two neutral Higgs bosons are estimated to be 80 and 125 GeV for some
parameter values in our model, which, are consistent with LEP2 data.Comment: 18 pages, 3figure
Spontaneous CP Violation in Non-Minimal Supersymmetric Models
We study the possibilities of spontaneous CP violation in the Next-to-Minimal
Supersymmetric Standard Model with an extra singlet tadpole term in the scalar
potential. We calculate the Higgs boson masses and couplings with radiative
corrections including dominant two loop terms. We show that it is possible to
satisfy the LEP constraints on the Higgs boson spectrum with non-trivial
spontaneous CP violating phases. We also show that these phases could account
for the observed value of epsilonK.Comment: 21 pages, 7 Figures in Encapsulated Postscrip
Weak Isospin Violations in Charged and Neutral Higgs Couplings from SUSY Loop Corrections
Supersymmetric QCD and supersymmetric electroweak loop corrections to the
violations of weak isospin to Yukawa couplings are investigated. Specifically
it involves an analysis of the supersymmetric loop corrections to the Higgs
couplings to the third generation quarks and leptons. Here we analyze the SUSY
loop corrections to the charged Higgs couplings which are then compared with
the supersymmetric loop corrections to the neutral Higgs couplings previously
computed. It is found that the weak isospin violations can be quite
significant, i.e, as much as 40-50% or more of the total loop correction to the
Yukawa coupling. The effects of CP phases are also studied and it is found that
these effects can either enhance or suppress the weak isospin violations. We
also investigate the weak isospin violation effects on the branching ratio
and show that the effects
are sensitive to CP phases. Thus an accurate measurement of this branching
ratio along with the branching ratio of the neutral Higgs boson decays can
provide a measure of weak isospin violation along with providing a clue to the
presence of supersymmetry.Comment: 20 pages, 9 figure
Electrochemical and Spectroscopic Study of Mononuclear Ruthenium Water Oxidation Catalysts: A Combined Experimental and Theoretical Investigation
Solid state NMR/Biophysical Organic Chemistr
Higgs Scalars in the Minimal Non-minimal Supersymmetric Standard Model
We consider the simplest and most economic version among the proposed
non-minimal supersymmetric models, in which the -parameter is promoted to
a singlet superfield, whose all self-couplings are absent from the
renormalizable superpotential. Such a particularly simple form of the
renormalizable superpotential may be enforced by discrete -symmetries which
are extended to the gravity-induced non-renormalizable operators as well. We
show explicitly that within the supergravity-mediated supersymmetry-breaking
scenario, the potentially dangerous divergent tadpoles associated with the
presence of the gauge singlet first appear at loop levels higher than 5 and
therefore do not destabilize the gauge hierarchy. The model provides a natural
explanation for the origin of the -term, without suffering from the
visible axion or the cosmological domain-wall problem. Focusing on the Higgs
sector of this minimal non-minimal supersymmetric standard model, we calculate
its effective Higgs potential by integrating out the dominant quantum effects
due to stop squarks. We then discuss the phenomenological implications of the
Higgs scalars predicted by the theory for the present and future high-energy
colliders. In particular, we find that our new minimal non-minimal
supersymmetric model can naturally accommodate a relatively light charged Higgs
boson, with a mass close to the present experimental lower bound.Comment: 63 pages (12 figures), extended versio
CP Violation in Supersymmetric U(1)' Models
The supersymmetric CP problem is studied within superstring-motivated
extensions of the MSSM with an additional U(1)' gauge symmetry broken at the
TeV scale. This class of models offers an attractive solution to the mu problem
of the MSSM, in which U(1)' gauge invariance forbids the bare mu term, but an
effective mu parameter is generated by the vacuum expectation value of a
Standard Model singlet S which has superpotential coupling of the form SH_uH_d
to the electroweak Higgs doublets. The effective mu parameter is thus
dynamically determined as a function of the soft supersymmetry breaking
parameters, and can be complex if the soft parameters have nontrivial
CP-violating phases. We examine the phenomenological constraints on the
reparameterization invariant phase combinations within this framework, and find
that the supersymmetric CP problem can be greatly alleviated in models in which
the phase of the SU(2) gaugino mass parameter is aligned with the soft
trilinear scalar mass parameter associated with the SH_uH_d coupling. We also
study how the phases filter into the Higgs sector, and find that while the
Higgs sector conserves CP at the renormalizable level to all orders of
perturbation theory, CP violation can enter at the nonrenormalizable level at
one-loop order. In the majority of the parameter space, the lightest Higgs
boson remains essentially CP even but the heavier Higgs bosons can exhibit
large CP-violating mixings, similar to the CP-violating MSSM with large mu
parameter.Comment: 29 pp, 3 figs, 2 table
Higgs and neutrino sector, EDM and epsilon_K in a spontaneously CP and R-parity breaking supersymmetric model
We construct an extension of the supersymmetric standard model where both CP
symmetry and R-parity are spontaneously broken. We study the electroweak
symmetry breaking sector of the model and find minima consistent with the
experimental bounds on Higgs boson masses. Neutrino masses and mixing angles
are generated through both seesaw and bilinear R-parity violation. We show that
the hierarchical mass pattern is obtained, and mixings are consistent with
measured values. Due to the spontaneous CP and R-parity violation, the neutrino
sector is CP violating, and we calculate the corresponding phase. We further
restrict the parameter space to agree with the limits on the electric dipole
moment of the neutron. Finally, we study the CP violation parameter epsilon_K
in the kaon system and show that we obtain results consistent with the
experimental value.Comment: 13 pages, 7 figures, submitted to EPJ
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