480 research outputs found
Two-Time Correlation Functions: Stochastic and Conventional Quantum Mechanics
An investigation of two-time correlation functions is reported within the
framework of (i) Stochastic Quantum Mechanics and (ii) conventional
Heisenberg-Schr\"odinger Quantum Mechanics. The spectral functions associated
with the two-time electric dipole correlation functions are worked out in
detail for the case of the hydrogen atom. While the single time averages are
identical for stochastic and conventional quantum mechanics, differences arise
in the two approaches for multiple time correlation functions.Comment: Version published by the Eur. Phys. J. B. Few references added. Minor
typos correcte
Neutrinoless Double Decay with Composite Neutrinos
We study in detail the contribution of heavy composite Majorana neutrinos to neutrino-less double beta decay. Our analysis confirms the result of a previous estimate by two of the authors. Excited neutrinos couple to the electroweak gauge bosons through a magnetic type effective Lagrangian. The relevant nuclear matrix element is related to matrix elements available in the literature and current bounds on the half-life of neutrino-less double beta decay are converted into bounds on the compositeness scale and/or the heavy neutrino mass. Our bounds are of the same order of magnitude as those available from accelerator experiments
Electric Dipole Moments and Polarizability in the Quark-Diquark Model of the Neutron
For a bound state internal wave function respecting parity symmetry, it can
be rigorously argued that the mean electric dipole moment must be strictly
zero. Thus, both the neutron, viewed as a bound state of three quarks, and the
water molecule, viewed as a bound state of ten electrons two protons and an
oxygen nucleus, both have zero mean electric dipole moments. Yet, the water
molecule is said to have a nonzero dipole moment strength with
. The neutron may also be said to have
an electric dipole moment strength with .
The neutron analysis can be made experimentally consistent, if one employs a
quark-diquark model of neutron structure.Comment: four pages, two figure
Comparative West Nile virus detection in organs of naturally infected American Crows (Corvus brachyrhynchos).
Widespread deaths of American Crows (Corvus brachyrhynchos)were associated with the 1999 outbreak of West Nile (WN) virus in the New York City region. We compared six organs from 20 crow carcasses as targets for WN virus detection. Half the carcasses had at least one positive test result for WN virus infection. The brain was the most sensitive test organ; it was the only positive organ for three of the positive crows. The sensitivity of crow organs as targets for WN virus detection makes crow death useful for WN virus surveillance
New Physics Potential with a Neutrino Telescope
Active Galactic Nuclei are considered as sources of neutrinos, with neutrino
energies extending up to 10^{18} eV. It is expected that these highly energetic
cosmic neutrinos will be detected by the neutrino telescopes, presently under
construction. The detection process is very sensitive to the total muon
neutrino cross-section. We examine how the total cross section changes at high
energies, by the single production of excited fermions (excited muon and
muon-neutrino). For parameters (masses, couplings) of the excited fermions
allowed by the experimental constraints, we find that for energies of the
incoming muon-neutrino above 100 TeV the cross-section for single production of
(excited muon and muon-neutrino) supersedes the standard total cross-section.Comment: 12 pages and 2 figures; typset using revtex; postscript files for the
figures provide
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