1,027,130 research outputs found
Momentum Space Integral Equations for Three Charged Particles: Diagonal Kernels
It has been a long-standing question whether momentum space integral
equations of the Faddeev type are applicable to reactions of three charged
particles, in particular above the three-body threshold. For, the presence of
long-range Coulomb forces has been thought to give rise to such severe
singularities in their kernels that the latter may lack the compactness
property known to exist in the case of purely short-range interactions.
Employing the rigorously equivalent formulation in terms of an
effective-two-body theory we have proved in a preceding paper [Phys. Rev. C
{\bf 61}, 064006 (2000)] that, for all energies, the nondiagonal kernels
occurring in the integral equations which determine the transition amplitudes
for all binary collision processes, possess on and off the energy shell only
integrable singularities, provided all three particles have charges of the same
sign, i.e., all Coulomb interactions are repulsive. In the present paper we
prove that, for particles with charges of equal sign, the diagonal kernels, in
contrast, possess one, but only one, nonintegrable singularity. The latter can,
however, be isolated explicitly and dealt with in a well-defined manner. Taken
together these results imply that modified integral equations can be
formulated, with kernels that become compact after a few iterations. This
concludes the proof that standard solution methods can be used for the
calculation of all binary (i.e., (in-)elastic and rearrangement) amplitudes by
means of momentum space integral equations of the effective-two-body type.Comment: 36 pages, 2 figures, accepted for publication in Phys. Rev.
CP violation in the lepton flavor violating interactions mu -> e gamma and tau -> mu gamma
We calculate the possible CP violating asymmetries for LFV decays mu -> e
gamma and tau -> mu gamma. Our predictions depend on the chosen new model
independent contribution. The result of measurements of such asymmetries for
these decays will open a new window to determine the physics beyond the SM.Comment: 7 pages, 12 Figure
The annihilation cross section of dark matter which is driven by scalar unparticle
We analyze the annihilation cross section of dark matter which interacts with
the standard model sector over the scalar unparticle propagator. We observe
that the annihilation cross section of dark matter pair is sensitive to the
dark matter mass and the scaling dimension of scalar unparticle. We estimate a
range for the dark matter mass and the scaling dimension of scalar unparticle
by using the current dark matter abundance.Comment: 9 pages, 4 figure
Toggle mechanism for pinching metal tubes
A toggle mechanism pinches a metal tube and maintains the tube in a pinched condition, without fracturing. The toggle mechanism includes a plunger translatable along a longitudinal axis, as well as a pair of links pivoted about a common axis extending through an end of the plunger. One of the links also pivots about a fixed axis. A free end of the other link carries a push link which the other link translates at right angles to the plunger longitudinal axis. First and second sides of the tube bear against a first stop block and are engaged by the push link when a compression spring, attached to the plunger, is suddenly released to irreversibly drive the plunger along its longitudinal axis so the pivot point of the two links is driven to an over travel position
A comparative study of Zinc (II) ions removal by a locally produced Granular activated carbon
Physiochemical properties of wastewater effluent from the plants of a brewery in Lagos, Nigeria were analyzed. The adsorption capacity of
Granular activated carbon from animal horns when compared with the available commercial Granulated Activated Carbon (GAC) has
been presented. Kinetics of adsorption was also investigated. The adsorption isotherms could be well defined with Freundlich model
instead of Langmuir model for both GAC studied. The experimental data, when applied to the first and second-order kinetic models,
followed the first-order with r² = 0.931 for GAC from animal horns while commercial GAC followed the second-order with r² = 0.936. The
results illustrated how animal horns, a solid waste disposal menace from the abattoir at the Oshodi market in Lagos metropolis, was used
as an effective biosorbent for the removal of Zn
2+
ions; offering a cheap option for primary treatment of the wastewater effluent
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