874 research outputs found
LEP Indications for Two Light Higgs Bosons and U(1)' Model
Reanalyses of LEP data have shown preference to two light CP-even Higgs
bosons. We discuss implications of such a Higgs boson spectrum for the minimal
supersymmetric model extended by a Standard Model singlet chiral superfield and
an additional Abelian gauge invariance (the U(1)' model). We, in particular,
determine parameter regions that lead to two light CP-even Higgs bosons while
satisfying existing bounds on the mass and mixings of the extra vector boson.
In these parameter regions, the pseudoscalar Higgs is found to be nearly
degenerate in mass with either the lightest or next-to-lightest Higgs boson.
Certain parameters of the U(1)' model such as the effective mu parameter are
found to be significantly bounded by the LEP two-light-Higgs signal.Comment: 20 pp, 7 figs, 2 table
Sigma-meson and omega-rho mixing effects in omega --> pi^+ pi^- gamma decay
We calculate the branching ratio of omega --> pi^+ pi^- gamma decay in a
phenomenological framework in which the contributions of VMD, chiral loops,
sigma-meson intermediate state amplitudes and the effects of omega-rho mixing
are considered. We conclude that the sigma-meson intermediate state amplitude
and omega-rho mixing make substantial contribution to the branching ratio.Comment: 10 pages RevTex, 4 Figures, to be published in Acta Phys. Pol.
b --> s g g decay in the two and three Higgs doublet models with CP violating effects
We study the decay width and CP-asymmetry of the inclusive process b--> s g g
(g denotes gluon) in the three and two Higgs doublet models with complex Yukawa
couplings. We analyse the dependencies of the differential decay width and
CP-asymmetry to the s- quark energy E_s and CP violating parameter \theta. We
observe that there exist a considerable enhancement in the decay width and CP
asymmetry is at the order of 10^{-2}. Further, it is possible to predict the
sign of C_7^{eff} using the CP asymmetry.Comment: 15 pages, 7 Figures (required epsf style
A Conceptual Model for Climatic-responsive Vernacular Architectural Forms
Indoor lighting, in terms of its spatial coverage, spectral range and extent is closely associated with occupants’ behaviour, yet little is known about its links with now-abandoned 19th century vernacular architectural forms of dry-and-arid climates in central Asia. Sustainable use of energy for domestic purposes is a critical component of the resilience of urban systems to urban sprawl (and escalating energy demands), mineral resource shortage and changing climate. Domestic energy use is a function of occupants’ behaviour in adjusting themselves to space through movement, which is driven by interrelated light-space-time. A better understanding of such interactions, in the context of energy efficient Iranian vernacular architecture can allow the adoption of traditional styles in design of contemporary indoor living spaces, thereby indirectly influencing occupants’ lifestyles towards lesser use of artificial lighting and energy conservation. It is in trying to understand how vernacular style can be turned into purposeful action that each core domain of vernacular architecture, and the dynamic of light and human through them, should be determined and brought to bear. In doing so, we present a conceptual model, built through field observations - of five three historical buildings in Kashan, Central Iran - interview and archival studies. The model informs on how occupant’s perception of space and response varies with time, space configuration and lighting levels
In-situ spectroscopy of intrinsic Bi2Te3 topological insulator thin films and impact of extrinsic defects
Combined in-situ x-ray photoemission spectroscopy, scanning tunnelling
spectroscopy and angle resolved photoemission spectroscopy of molecular beam
epitaxy grown Bi2Te3 on lattice mismatched substrates reveal high quality
stoichiometric thin films with topological surface states without a
contribution from the bulk bands at the Fermi energy. The absence of bulk
states at the Fermi energy is achieved without counter doping. We observe that
the surface morphology and electronic band structure of Bi2Te3 are not affected
by in-vacuo storage and exposure to oxygen, whereas major changes are observed
when exposed to ambient conditions. These films help define a pathway towards
intrinsic topological devices.Comment: 8 pages, 5 figure
Petroleum-Collecting And Dispersing Chemicals For Cleaning Sea Surface From Thin Petroleum Slicks
Monoethylolamide, diethylolamide and triethanolamine ester synthesized by us
based on fish oil and their phosphate derivatives being surface-active and ecologically safe possess
a high capacity of petroleum collecting and dispersing. When introducing phosphate group, a
tendency to replacement of petroleum slick dispersing by its collection (accumulation into a spot)
is observed. Efficiency of the chemicals change depends on the type and concentration of ions in
the water. Such salts as NaCl, KI, KBr, and MgSO4 positively influence petroleum-collecting
activity whereas K2CO3 and NaHCO3 cause petroleum dispersing
Tevatron Higgs Mass Bounds: Projecting U(1)' Models to LHC Domain
We study Higgs boson masses in supersymmetric models with an extra U(1)
symmetry to be called U(1). Such extra gauge symmetries are urged by
the problem of the MSSM, and they also arise frequently in low-energy
supersymmetric models stemming from GUTs and strings. We analyze mass of the
lightest Higgs boson and various other particle masses and couplings by taking
into account the LEP bounds as well as the recent bounds from Tevatron
experiments. We find that the -problem motivated generic low-energy
U(1) model yields Higgs masses as large as and
violate the Tevatron bounds for certain ranges of parameters. We analyze
correlations among various model parameters, and determine excluded regions by
both scanning the parameter space and by examining certain likely parameter
values. We also make educated projections for LHC measurements in light of the
Tevatron restrictions on the parameter space. We further analyze certain
benchmark models stemming from E(6) breaking, and find that they elevate Higgs
boson mass into Tevatron's forbidden band when U(1) gauge coupling
takes larger values than the one corresponding to one-step GUT breaking.Comment: 11 pages, 3 figure
FACTORS ASSOCIATED WITH HIP INVOLVEMENT AND ITS IMPACT ON TREATMENT DECISION IN PATIENTS WITH AXIAL SPONDYLOARTHRITIS; TREASURE EXPERIENCE
[Abstract Not Available
Rebaudioside A inhibits pentylenetetrazol-induced convulsions in rats
AbstractThe safety of patients with epilepsy consuming sweetening agents, which is becoming increasingly prevalent for various reasons, is a topic that should be emphasized as sensitively as it is for other diseases. Patients with epilepsy consume sweetening agents for different reasons such being diabetic or overweight. They can occasionally be exposed to sweetening agents unrestrainedly through consuming convenience food, primarily beverages. This study aimed to investigate the effects of rebaudioside A (Reb-A), which is a steviol glycoside produced from the herb Stevia rebaudiana (Bertoni), on epileptic seizures and convulsions induced by pentylenetetrazole (PTZ). Forty-eight male rats were used. Twenty-four rats were administered 35 mg/kg PTZ to trigger epileptiform activity; the remaining 24 rats were administered 70 mg/kg PTZ to trigger the convulsion model. The epileptiform activity was evaluated by spike percentage, whereas convulsion was evaluated by Racine's Convulsion Scale and the onset time of the first myoclonic jerk. Statistical analysis revealed a statistically significant decrease in the Racine's Convulsion Scale score and increase in the latency of first myoclonic jerk in a dose-dependent manner for the rat groups in which PTZ epilepsy had been induced and Reb-A had been administered. For the groups that were administered Reb-A, the spike decrease was apparent in a dose-dependent manner, based on the spike percentage calculation. These results indicated that Reb-A has positive effects on PTZ-induced convulsions
CP violation in the inclusive b -> s g decay in the framework of multi Higgs doublet models
We study the decay width and CP asymmetry of the inclusive process b--> s g
(g denotes gluon) in the multi Higgs doublet models with complex Yukawa
couplings, including next to leading QCD corrections. We analyse the
dependencies of the decay width and CP asymmetry on the scale \mu and CP
violating parameter \theta. We observe that there exist an enhancement in the
decay width and CP asymmetry is at the order of 10^{-2}.Comment: 11 pages, 8 Figure
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