20,930 research outputs found
Quantumness beyond quantum mechanics
Bohmian mechanics allows us to understand quantum systems in the light of
other quantum traits than the well-known ones (coherence, diffraction,
interference, tunneling, discreteness, entanglement, etc.). Here the discussion
focusses precisely on two of these interesting aspects, which arise when
quantum mechanics is though within this theoretical framework: the non-crossing
property, which allows for distinguishability without erasing interference
patterns, and the possibility to define quantum probability tubes, along which
the probability remains constant all the way. Furthermore, taking into account
this hydrodynamic-like description as a link, it is also shown how this
knowledge (concepts and ideas) can be straightforwardly transferred to other
fields of physics (for example, the transmission of light along waveguides).Comment: 11 pages, 4 figures; based on a talk at the Conference "Emergent
Quantum Mechanics" / 5th Heinz von Foerster Congress (Vienna, Nov 11-13,
2011
How far can a pragmatist go into quantum theory? - A critical view of our current understanding of quantum phenomena
To date, quantum mechanics has proven to be our most successful theoretical
model. However, it is still surrounded by a "mysterious halo" that can be
summarized in a simple but challenging question: Why quantum phenomena are not
understood under the same logic as classical ones? Although this is an open
question (probably without an answer), from a pragmatist's point of view there
is still room enough to further explore the quantum world, marveling ourselves
with new physical insights. We just need to look back in the historical
evolution of the quantum theory and thoroughly reconsider three key issues: (1)
how this has developed since its early stages at a conceptual level, (2) what
kind of experiments can be performed at present in a laboratory, and (3) what
nonstandard conceptual models are available to extract some extra information.
This contribution is aimed at providing some answers (and, perhaps, also
raising some issues) to these questions through one of such models, namely
Bohmian mechanics, a hydrodynamic formulation of the quantum theory, which is
currently trying to open new pathways of understanding. Specifically, the
Chapter constitutes a brief and personal overview on the historic and
contextual evolution of this quantum formulation, its physical meaning and
interest (leaving aside metaphysical issues), and how it may help to overcome
some preconceived paradoxical aspects of the quantum theory.Comment: 11 pages, 2 figures; contribution to "Particle and Astroparticle
Physics, Gravitation and Cosmology: Predictions, Observations and New
Projects" (Proceedings of the XXXth International Workshop on High Energy
Physics), eds. V. Petrov and R. Ryutin (World Scientific, Singapore, 2015),
pp. 161-17
Limits on anomalous couplings of the Higgs boson to electroweak gauge bosons from LEP and the LHC
In this paper we assume the Higgs is an elementary scalar, and study how new physics could affect its couplings to electroweak gauge bosons. Adding LHC data to LEP data provides new, more stringent limits, particularly when the Higgs to two photon decay signal strength is taken into account. We then study the effect of anomalous angular correlations in the decay to WW*. We obtain a new limit on the rare decay to photon-Z, and use it to constrain supersymmetry, to find that staus with large mixing would be most sensitive to this channel. We also use these limits to constrain radion exchange in warped extra dimensions, finding a limit on the radion mass and interaction scale of the order of TeV. Finally, we have extrapolated the current data to obtain prospects for the full 2012 data set
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