1,318 research outputs found
Indirect Effect of Supersymmetric Triplets in Stop Decays
We study an extension of the minimal supersymmetric standard model with a
zero hypercharge triplet, and the effect that such a particle has on stop
decays. This model has the capability of predicting a 125.5 GeV Higgs even in
the presence of light stops and it can modify the diphoton rate by means of the
extra charged fermion triplet coupled to the Higgs. Working in the limit where
the scalar triplet decouples, and with small values of mA, we find that the
fermion triplet can greatly affect the branching ratios of the stops, even in
the absence of a direct stop-triplet coupling. We compare the triplet extension
with the MSSM and discuss how the additional fields affect the search for stop
pair production.Comment: pdfLateX, 16 pages, 7 figures, 2 tables, Typos, minor changes.
Version published in JHE
Phantom Higgs from Unparticles
A renormalizable coupling between the Higgs and a scalar unparticle operator
O_U of non-integer dimension d_U < 2 gives rise, after electroweak symmetry
breaking, to a mass gap in the unparticle continuum and a shift in the original
Higgs mass, which can end up above or below the mass gap. We show that, besides
the displaced Higgs state, a new isolated state can generically appear in the
spectrum near or below the mass gap. Such state (which we call phantom Higgs)
is a mixture of Higgs and unparticles and therefore has universally reduced
couplings to fermions and gauge bosons. This phenomenon could cause the mass of
the lightest Higgs state accessible to colliders to be much smaller than the
mass expected from the SM Lagrangian.Comment: 14 LaTeX pages, 6 figure
Brans-Dicke-type theories and avoidance of the cosmological singularity
We tudy flat Friedmann-Robertson-Walker cosmology in Brans-Dicke-type
theories of gravitation with minimal coupling between the scalar field and the
matter fields in the Einstein frame (general relativity with an extra scalar
field) for arbitrary values of the Brans-Dicke parameter . It is
shown that the cosmological singularity occuring in the Einstein frame
formulation of this theory is removed in the Jordan frame in the range
. This result is interpreted in the ligth of a
viewpoint (first presented in reference gr-qc/9905071) asserting that both
Jordan frame and Einstein frame formulations of general relativity are
physically equivalent. The implications of the obtained result for string
theory are outlined.Comment: 9 pages, LaTeX, no figures. Improved version accepted for publication
in PR
Steganalysis of Hydan
Hydan is a steganographic tool which can be used to hide any kind of information inside executable files. In this work, we present an efficient distinguisher for it: We have developed a system that is able to detect executable files with embedded information through Hydan. Our system uses statistical analysis of instruction set distribution to distinguish between files with no hidden information and files that have been modified with Hydan. We have tested our algorithm against a mix of clean and stego-executable files. The proposed distinguisher is able to tell apart these files with a 0 ratio of false positives and negatives, thus detecting all files with hidden information through Hydan
Effective Monopoles within Thick Branes
The monopole mass is revealed to be considerably modified in the thick
braneworld paradigm, and depends on the position of the monopole in the brane
as well. Accordingly, the monopole radius continuously increases, leading to an
unacceptable setting that can be circumvented when the brane thickness has an
upper limit. Despite such peculiar behavior, the quantum corrections accrued --
involving the classical monopole solution -- are shown to be still under
control. We analyze the monopole's peculiarities also taking into account the
localization of the gauge fields. Furthermore, some additional analysis in the
thick braneworld context and the similar behavior evinced by the topological
string are investigated.Comment: 7 pages, 1 figur
Higgs Mediated EDMs in the Next-to-MSSM: An Application to Electroweak Baryogenesis
We perform a study on the predictions of electric-dipole moments (EDMs) of
neutron, Mercury (Hg), Thallium (Tl), deuteron, and Radium (Ra) in the
framework of next-to-minimal supersymmetric standard model (NMSSM) with
CP-violating parameters in the superpotential and soft-supersymmetry-breaking
sector. We confine to the case in which only the physical tree-level CP phase
, associated with the couplings of the singlet
terms in the superpotential and with the vacuum-expectation-values (VEVs),
takes on a nonzero value. We found that the one-loop contributions from
neutralinos are mostly small while the two-loop Higgs-mediated contributions of
the Barr-Zee (BZ) type diagrams dominate. We emphasize a scenario motivated by
electroweak baryogenesis.Comment: 36 pages, 9 figures, to appear in PR
Scherk-Schwarz SUSY breaking from the viewpoint of 5D conformal supergravity
We reinterpret the Scherk-Schwarz (SS) boundary condition for SU(2)_R in a
compactified five-dimensional (5D) Poincare supergravity in terms of the
twisted SU(2)_U gauge fixing in 5D conformal supergravity. In such translation,
only the compensator hypermultiplet is relevant to the SS twist, and various
properties of the SS mechanism can be easily understood. Especially, we show
the correspondence between the SS twist and constant superpotentials within our
framework.Comment: 16 pages, no figur
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