7,511 research outputs found
THE PROPOSED UNITED STATES-MEXICO-CANADA NORTH AMERICAN FREE TRADE AGREEMENT: THE MEXICAN PERSPECTIVE
International Relations/Trade,
CURRENT STATE AND FUTURE DIRECTIONS OF SAEA
Teaching/Communication/Extension/Profession,
Absolute neutrino mass and the Dirac/Majorana distinction from the weak interaction of aggregate matter
The 2-mediated force has a range of microns, well beyond the atomic
scale. The effective potential is built from the t-channel absorptive part of
the scattering amplitude and depends on neutrino properties on-shell. We
demonstrate that neutral aggregate matter has a weak charge and calculate the
matrix of six coherent charges for its interaction with definite-mass
neutrinos. Near the range of the potential the neutrino pair is
non-relativistic, leading to observable absolute mass and Dirac/Majorana
distinction via different r-dependence and violation of the weak equivalence
principle.Comment: 6 pages, 3 figures, 1 tabl
Stimulated transitions in resonant atom Majorana mixing
Massive neutrinos demand to ask whether they are Dirac or Majorana particles.
Majorana neutrinos are an irrefutable proof of physics beyond the Standard
Model. Neutrinoless double electron capture is not a process but a virtual
mixing between a parent atom and a daughter
excited atom with two electron holes. As a mixing between two neutral atoms and
the observable signal in terms of emitted two-hole X-rays, the strategy,
experimental signature and background are different from neutrinoless double
beta decay. The mixing is resonantly enhanced for almost degeneracy and, under
these conditions, there is no irreducible background from the standard
two-neutrino channel. We reconstruct the natural time history of a nominally
stable parent atom since its production either by nature or in the laboratory.
After the time periods of atom oscillations and the decay of the short-lived
daughter atom, at observable times the relevant "stationary" states are the
mixed metastable long-lived state and the non-orthogonal short-lived excited
state, as well as the ground state of the daughter atom. We find that they have
a natural population inversion which is most appropriate for exploiting the
bosonic nature of the observed atomic transitions radiation. Among different
observables of the atom Majorana mixing, we include the enhanced rate of
stimulated X-ray emission from the long-lived metastable state by a
high-intensity X-ray beam: a gain factor of 100 can be envisaged at current
XFEL facilities. On the other hand, the historical population of the daughter
atom ground state can be probed by exciting it with a current pulsed optical
laser, showing the characteristic absorption lines: the whole population can be
excited in a shorter time than typical pulse duration.Comment: 17 pages, 4 figure
Flow Smoothing and Denoising: Graph Signal Processing in the Edge-Space
This paper focuses on devising graph signal processing tools for the
treatment of data defined on the edges of a graph. We first show that
conventional tools from graph signal processing may not be suitable for the
analysis of such signals. More specifically, we discuss how the underlying
notion of a `smooth signal' inherited from (the typically considered variants
of) the graph Laplacian are not suitable when dealing with edge signals that
encode a notion of flow. To overcome this limitation we introduce a class of
filters based on the Edge-Laplacian, a special case of the Hodge-Laplacian for
simplicial complexes of order one. We demonstrate how this Edge-Laplacian leads
to low-pass filters that enforce (approximate) flow-conservation in the
processed signals. Moreover, we show how these new filters can be combined with
more classical Laplacian-based processing methods on the line-graph. Finally,
we illustrate the developed tools by denoising synthetic traffic flows on the
London street network.Comment: 5 pages, 2 figur
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