4,253 research outputs found
Fermion masses in noncommutative geometry
Recent indications of neutrino oscillations raise the question of the
possibility of incorporating massive neutrinos in the formulation of the
Standard Model (SM) within noncommutative geometry (NCG). We find that the NCG
requirement of Poincare duality constrains the numbers of massless quarks and
neutrinos to be unequal unless new fermions are introduced. Possible scenarios
in which this constraint is satisfied are discussed.Comment: 4 pages, REVTeX; typos are corrected in (19), "Possible Solutions"
and "Conclusion" are modified; additional calculational details are included;
references are update
K-Shell Auger Spectrum Of Atomic Oxygen
We have observed the K-shell Auger spectrum in atomic oxygen. A total of ten transitions originating from the decay of the 4P and 2P states of the O+(1s-1) ion are identified and assigned to final states of the O2+ ion. Relative intensities for each of these transitions are obtained, allowing the extraction of the dependence of the Auger decay on the multiplet structure in both the initial and final states of this basic open-shell atom
A Study of Naturally Occurring Algicides Produced by Freshwater Algae
The mode of action of the algicide produced by Pandorina morum was examined by exposing Volvox globator and isolates spinach chloroplasts to a partially purified algicide preparation. Oxygen evolution of Volvox, whole chloroplasts and broken chloroplasts (minus the Calvin cycle),was reduced indicating that the algicide inhibits the light reactions of photosynthesis. Oxygen evolution studies of other Volvocaceae confirmed the observation that Pandorina morum is not significantly influenced by its own inhibitor. Molecular weight approximation by gel filtration established that the inhibitor has a low molecular weight (probably below 100 mw). Field studies indicate that this algicide has tremendous potential as a control for the growth of nuisance algal growth
Large Extra Dimensions, Sterile neutrinos and Solar Neutrino Data
Solar, atmospheric and LSND neutrino oscillation results require a light
sterile neutrino, , which can exist in the bulk of extra dimensions.
Solar , confined to the brane, can oscillate in the vacuum to the zero
mode of and via successive MSW transitions to Kaluza-Klein states of
. This new way to fit solar data is provided by both low and
intermediate string scale models. From average rates seen in the three types of
solar experiments, the Super-Kamiokande spectrum is predicted with 73%
probability, but dips characteristic of the 0.06 mm extra dimension should be
seen in the SNO spectrum.Comment: 4 pages, 2 figure
Analogy, Dirac-Majorana Neutrino Duality and the Neutrino Oscillations
The intent of this paper is to convey a new primary physical idea of a
Dirac-Majorana neutrino duality in relation to the topical problem of neutrino
oscillations. In view of the new atmospheric, solar and the LSND neutrino
oscillation data, the Pontecorvo oscillation analogy is generalized
to the notion of neutrino duality with substantially different physical meaning
ascribed to the long-baseline and the short-baseline neutrino oscillations. At
the level of CP-invariance, the suggestion of dual neutrino properties defines
the symmetric two-mixing-angle form of the widely discussed four-neutrino
-mixing scheme, as a result of the lepton charge conservation selection
rule and a minimum of two Dirac neutrino fields. With neutrino duality, the
two-doublet structure of the Majorana neutrino mass spectrum is a vestige of
the two-Dirac-neutrino origin. The fine neutrino mass doublet structure is
natural because it is produced by a lepton charge symmetry violating
perturbation on a zero-approximation system of two twofold mass-degenerate
Dirac neutrino-antineutrino pairs. A set of inferences related to the neutrino
oscillation phenomenology in vacuum is considered.Comment: 13 pages, LaTeX. Minor modifications, new references adde
Stringent constraint on the scalar-neutrino coupling constant from quintessential cosmology
An extremely light (), slowly-varying scalar
field (quintessence) with a potential energy density as large as 60% of
the critical density has been proposed as the origin of the accelerated
expansion of the Universe at present. The interaction of this smoothly
distributed component with another predominately smooth component, the cosmic
neutrino background, is studied. The slow-roll approximation for generic potentials may then be used to obtain a limit on the scalar-neutrino coupling
constant, found to be many orders of magnitude more stringent than the limits
set by observations of neutrinos from SN 1987A. In addition, if quintessential
theory allows for a violation of the equivalence principle in the sector of
neutrinos, the current solar neutrino data can probe such a violation at the
10^{-10} level.Comment: 7 pages, MPLA in press, some parts disregarded and a footnote adde
1968 Costs for Field Work
Four methods of figuring your field work are included in this article. One is a guide of costs taken from actual costs on the university farms, which reflects some of the recent increases
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