287,112 research outputs found
Diffusion-convection function of cosmic rays
The fundamental properties and some numerical results of the solution of the diffusion equation of an impulsive cosmic-ray point source in an uniform, unbounded and spherically symmetrical moving medium is presented. The diffusion-convection(D-C) function is an elementary composite function of the solution of the D-C equation for the particles injected impulsively from a diffusive point source into the medium. It is the analytic solution derived by the dimensional method for the propagation equation of solar cosmic rays in the heliosphere, i.e. the interplanetary space. Because of the introduction of convection effect of solar wind, a nonhomogeneous term appears in the propagation equation, it is difficult to express its solution in terms of the ordinary special functions. The research made so far has led to a solution containing only the first order approximation of the convection effect
Baryons as Solitons in Three Dimensional Quantum Chromodynamics
We show that baryons of three dimensional Quantum Chromodynamics can be
understood as solitons of its effective lagrangian. In the parity preserving
phase we study, these baryons are fermions for odd and bosons for even
, never anyons. We quantize the collective variables of the solitons and
there by calculate the flavor quantum numbers, magnetic moments and mass
splittings of the baryon. The flavor quantum numbers are in agreement with
naive quark model for the low lying states. The magnetic moments and mass
splittings are smaller in the soliton model by a factor of . We also show that there is a dibaryon solution that is an analogue
of the deuteron. These solitons can describe defects in a quantum
anti--ferromagnet.Comment: 22 pages + 4 figures (figures not included, postscript files
available upon request
The Effective Lagrangian of Three Dimensional Quantum Chromodynamics
We consider the low energy limit of three dimensional Quantum Chromodynamics
with an even number of flavors. We show that Parity is not spontaneously
broken, but the global (flavor) symmetry is spontaneously broken. The low
energy effective lagrangian is a nonlinear sigma model on the Grassmannian.
Some Chern--Simons terms are necessary in the lagrangian to realize the
discrete symmetries correctly. We consider also another parametrization of the
low energy sector which leads to a three dimensional analogue of the
Wess--Zumino--Witten--Novikov model. Since three dimensional QCD is believed to
be a model for quantum anti--ferromagnetism, our effective lagrangian can
describe their long wavelength excitations (spin waves).Comment: 18 page
Three Dimensional Quantum Chromodynamics
The subject of this talk was the review of our study of three ()
dimensional Quantum Chromodynamics. In our previous works, we showed the
existence of a phase where parity is unbroken and the flavor group is
broken to a subgroup . We derived the low energy effective
action for the theory and showed that it has solitonic excitations with Fermi
statistic, to be identified with the three dimensional ``baryon''. Finally, we
studied the current algebra for this effective action and we found a
co-homologically non trivial generalization of Kac-Moody algebras to three
dimensions.Comment: 7 pages, Plain TEX, talk presented by S.G. Rajeev at the XXVI
INTERNATIONAL CONFERENCE ON HIGH ENERGY PHYSICS, DALLAS TX AUG. 199
High-voltage spark carbon-fiber sticky-tape data analyzer
An efficient method for detecting carbon fibers collected on a stick tape monitor was developed. The fibers were released from a simulated crash fire situation containing carbon fiber composite material. The method utilized the ability of the fiber to initiate a spark across a set of alternately biased high voltage electrodes to electronically count the number of fiber fragments collected on the tape. It was found that the spark, which contains high energy and is of very short duration, is capable of partially damaging or consuming the fiber fragments. It also creates a mechanical disturbance which ejects the fiber from the grid. Both characteristics were helpful in establishing a single discharge pulse for each fiber segment
Cryptanalyzing a discrete-time chaos synchronization secure communication system
This paper describes the security weakness of a recently proposed secure
communication method based on discrete-time chaos synchronization. We show that
the security is compromised even without precise knowledge of the chaotic
system used. We also make many suggestions to improve its security in future
versions.Comment: 11 pages, 3 figures, latex forma
Quantum steering of electron wave function in an InAs Y-branch switch
We report experiments on gated Y-branch switches made from InAs ballistic
electron wave guides. We demonstrate that gating modifies the electron wave
functions as well as their interference pattern, causing the anti-correlated,
oscillatory transconductances. Such previously unexpected phenomenon provides
evidence of steering the electron wave function in a multi-channel transistor
structure.Comment: 15 pages, including 3 figure
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