816 research outputs found
Muon as a composite fermion from the three charged electron-like leptons in the bound state in the continuum
For many-particle systems the mass of the bound states in the continuum (BIC)
is greater than the total mass of the initial particles. BICs which are stable
and not-decaying, have been found and studied in detail in various fields of
physics. But, as far as we know, in particle physics such states have not yet
been analyzed. The idea of this work is to apply the BIC phenomenon to some
elementary particles and, in particular, to the description of muons. This
study focuses on a composite fermion formed by the three charged electron-like
leptons in BIC, with the mass of 207 electron masses. The structure of the
positive charged composite fermion is formed by the two positron and the
electron, , and the negatively charged composite
fermion is considered as . In this theory the free
electron and free positron are treated as ordinary, different particles, each
being characterized by the complete set of the Dirac plane waves. The integral
equation for the wave function of the composite fermion is derived by using the
Bethe and Salpeter equation with account for the lowest order of the pair
interaction for the three particles. An approximate solution of this equation
gave results for the massive fermion wave function that predicted the particle
radius equal to 16 fm. The representation of the muon as the composite fermion
formed by the three charged electron-like leptons in BIC, is analyzed. Only in
the case of considering the electron and positron as ordinary, different
particles, the possible decay channels of this heavy composite fermion do not
contradict those for the muons.Comment: 16 pages, 5 figure
Reconstructing Images from Projections Using the Maximum-Entropy Method. Numerical Simulations of Low-Aspect Astrotomography
The reconstruction of images from a small number of projections using the
maximum-entropy method (MEM) with the Shannon entropy is considered. MEM
provides higher-quality image reconstruction for sources with extended
components than the Hogbom CLEAN method, which is also used in low-aspect
astrotomography. The quality of image reconstruction for sources with mixed
structure containing bright, compact features embedded in a comparatively weak,
extended base can be further improved using a difference-mapping method, which
requires a generalization of MEM for the reconstruction of sign-variable
functions.We draw conclusions based on the results of numerical simulations for
a number of model radio sources with various morphologies.Comment: 11 pages, 9 figure
High-visibility multi-photon interference of Hanbury Brown - Twiss type for classical light
Difference-phase (or Hanbury Brown - Twiss type) intensity interference of
classical light is considered in higher orders in the intensity. It is shown
that, while the visibility of sum-phase (NOON-type) interference for classical
sources drops with the order of interference, the visibility of
difference-phase interference has opposite behavior. For three-photon and
four-photon interference of two coherent sources, the visibility can be as high
as 81.8% and 94.4%, respectively. High-visibility three-photon and four-photon
interference of space-time and polarization types has been observed in
experiment, for both coherent and pseudo-thermal light.Comment: 11 pages, 9 figure
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