11,857 research outputs found
e^+e^-\to (h A)\to bbbb in Abelian Extended Supersymmetric Standard Model
We discuss the  cross section in an Abelian
extended SM. We work in that minimum of the scalar potential for which Higgs
trilier coupling is greater than the soft mass parameters. We find that
nex-to-lightest Higgs gives the essential contribution to the cross section in
the small  mixing angle and leptophobic  limit.Comment: 13 pages, 1 postscript figur
Investigations Of The Functional And Technological Properties Of Dough Semi-products Enriched With Dietary Supplements
The work is devoted to improving technologies of enriching food raw materials and products. The object of the research is dough semi-products of leavened, puff and unleavened dough, enriched with a dietary supplement, based on the chelate complex. The conducted studies are directed on investigating the evenness of distribution of microelements in the volume of dough semi-products and establishing the influence of a supplement on functional-technological properties of these semi-products. At that there were used methods of nuclear magnetic resonance, electronic paramagnetic resonance, low-temperature calorimetric method and rheological research methods. The method of nuclear magnetic resonance established that a dietary supplement, based on the chelate complex influences the mobility and interaction of water molecules with an environment in dough semi-products. The method of electronic paramagnetic resonance proved the evenness of distribution of a microelement of a dietary supplement by the volume of studied dough semi-product. Rheological and low-temperature calorimetric methods established that an introduced supplement favors a change of the qualitative and quantitative composition of system water of studied semi-products and changes their elastic properties. The obtained results proved the efficiency of using a powder-like supplement with stabilized chelates of metals in technologies of enriching food products
The Wilson loop from a Dyson equation
The Dyson equation proposed for planar temporal Wilson loops in the context
of supersymmetric gauge theories is critically analysed thereby exhibiting its
ingredients and approximations involved. We reveal its limitations and identify
its range of applicability in non-supersymmetric gauge theories. In particular,
we show that this equation is applicable only to strongly asymmetric planar
Wilson loops (consisting of a long and a short pair of loop segments) and as a
consequence the Wilsonian potential can be extracted only up to intermediate
distances. By this equation the Wilson loop is exclusively determined by the
gluon propagator. We solve the Dyson equation in Coulomb gauge for the temporal
Wilson loop with the instantaneous part of the gluon propagator and for the
spatial Wilson loop with the static gluon propagator obtained in the
Hamiltonian approach to continuum Yang-Mills theory and on the lattice. In both
cases we find a linearly rising color potential.Comment: 12 pages, 7 figure
Q-ball formation in the MSSM with explicit CP violation
Q-balls generically exist in the supersymmetric extensions of the standard
model. Taking into account the additional sources of CP violation, which are
naturally accomodated by the supersymmetric models, it is shown that the Q-ball
matter depends additively on individual CP phases, whereas mass per unit charge
in the Q-ball depends only on the relative phases. There are regions of the
parameter space where there is no stable Q-ball solution in the CP-conserving
limit whereas finite CP phases induce a stable Q-ball.Comment: 6 p
A note on the breathing mode of an elastic sphere in Newtonian and complex fluids
Experiments on the acoustic vibrations of elastic nanostructures in fluid
media have been used to study the mechanical properties of materials, as well
as for mechanical and biological sensing. The medium surrounding the
nanostructure is typically modeled as a Newtonian fluid. A recent experiment
however suggested that high-frequency longitudinal vibration of bipyramidal
nanoparticles could trigger a viscoelastic response in water-glycerol mixtures
[M. Pelton et al., "Viscoelastic flows in simple liquids generated by vibrating
nanostructures," Phys. Rev. Lett. 111, 244502 (2013)]. Motivated by these
experimental studies, we first revisit a classical continuum mechanics problem
of the purely radial vibration of an elastic sphere, also called the breathing
mode, in a compressible viscous fluid, and then extend our analysis to a
viscoelastic medium using the Maxwell fluid model. The effects of fluid
compressibility and viscoelasticity are discussed. Although in the case of
longitudinal vibration of bipyramidal nanoparticles, the effects of fluid
compressibility were shown to be negligible, we demonstrate that it plays a
significant role in the breathing mode of an elastic sphere. On the other hand,
despite the different vibration modes, the breathing mode of a sphere triggers
a viscoelastic response in water-glycerol mixtures similar to that triggered by
the longitudinal vibration of bipyramidal nanoparticles. We also comment on the
effect of fluid viscoelasticity on the idea of destroying virus particles by
acoustic resonance
Slowdown and splitting of gap solitons in apodized Bragg gratings
We study the motion of gap solitons in two models of apodized nonlinear fiber
Bragg gratings (BGs), with the local reflectivity (LR) varying along the fiber.
A single step of LR, and a periodic array of alternating steps with opposite
signs (a "Bragg superstructure") are considered. A challenging possibility is
to slow down and eventually halt the soliton by passing it through the step of
increasing reflectivity, thus capturing a pulse of standing light. First, we
develop an analytical approach, assuming adiabatic evolution of the soliton,
and making use of the energy conservation and balance equation for the
momentum. Comparison with simulations shows that the analytical approximation
is quite accurate (unless the inhomogeneity is too steep): the soliton is
either transmitted across the step or bounces back. If the step is narrow,
systematic simulations demontrate that the soliton splits into transmitted and
reflected pulses (splitting of a BG soliton which hits a chirped grating was
observed in experiments). Moving through the periodic "superstructure", the
soliton accummulates distortion and suffers radiation loss if the structure is
composed of narrow steps. The soliton moves without any loss or irreversible
deformation through the array of sufficiently broad steps.Comment: to appear in a special issue on Wave-Optical Engineering, Journal of
  Modern Optic
Unitarity of the tree approximation to the Glauber AA amplitude for large A
The nucleus-nucleus Glauber amplitude in the tree approximation is studied
for heavy participant nuclei. It is shown that, contrary to previous published
results, it is not unitary for realistic values of nucleon-nucleon
cross-sections.Comment: 15 pages, 1 figure, 1 table. Submitted to Yad. Fi
One-Loop Effects in Supergravity Models with an Additional U(1)
For an Abelian extended Supergravity model, we investigate some important low
energy parameters: \tan\beta, Z-Z' mixing angle, lightest CP-even Higgs mass
bound, Z' mass, and effective \mu parameter. By integrating the RGE's from
string scale down to the weak scale we constuct the scalar potential, and
analyze the quantities above at the tree- and one-loop levels by including the
contributions of top squarks and top quark in the effective potential. PACS:
04.65.+e, 12.60.JvComment: 16 pages, 6 postscript figure
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