2,774 research outputs found
Isotope shifts and hyperfine structure of the laser cooling Fe I 358-nm line
We report on the measurement of the isotope shifts of the Fe~I line at 358~nm between all four
stable isotopes Fe, Fe, Fe and Fe, as well
as the hyperfine structure of that line for Fe, the only stable
isotope having a nonzero nuclear spin. This line is of primary importance for
laser cooling applications. In addition, an experimental value of the field and
specific mass shift coefficients of the transition is reported as well as the
hyperfine structure magnetic dipole coupling constant of the transition
excited state in Fe, namely
MHz. The measurements were carried out by means of laser-induced fluorescence
spectroscopy performed on an isotope-enriched iron atomic beam. All measured
frequency shifts are reported with uncertainties below the third percent level.Comment: 5 pages, 5 figure
Baryogenesis in the MSSM, nMSSM and NMSSM
We compare electroweak baryogenesis in the MSSM, nMSSM and NMSSM. We comment
on the different sources of CP violation, the phase transition and constraints
from EDM measurements.Comment: 6 pages, 4 figures. To appear in the proceedings of the 7th
Conference on Strong and Electroweak Matter (SEWM06), Brookhaven National
Laboratory, May 10-13, 200
Overlap formulation of Majorana--Weyl fermions
An overlap method for regularizing Majorana--Weyl fermions interacting with
gauge fields is presented. A mod(2) index is introduced in relation to the
anomalous violation of a discrete global chiral symmetry. Most of the paper is
restricted to 2 dimensions but generalizations to 2+8k dimensions should be
straightforward.Comment: 8 pages, Plain Te
Sériation des gravures piquetées du mont Bego (Alpes-Maritimes, France)
The site of Mount Bego is one of the most important rock art concentrations in Europe for recent Prehistory. After a study conducted for more than 45 years by Henry de Lumley, the majority of the 4,000 engraved rocks have been positioned and the near 36,000 engravings have been drawn. The engravings were firstly attributed to Chalcolithic and Early Bronze Age, on the basis of a comparison between the engraved weapons and real weapons that have been discovered in an archaeological context. During his PhD (2012), the author carried out the first systematic geostatistical analysis of the entire corpus, bringing out a series of effects (iconographic and geographic seriation, preferential location, etc.) in the engravings distribution. Thanks to the study of superimpositions, these quantitative results allow to consider a periodization of the main families of engravings. While weapon representations appear to be the most recent layer of engravings, reticulated figures and schematic horned figures seem to be the most ancient ones. Therefore, dating on the basis of weapon representations can no longer be considered valid for the entire corpus of engravings. Besides, Mount Bego site shows early occupations, as documented by archaeological artefacts (Cardial ceramics, Chassean flints, Recent Bell Beaker ceramics, etc.) and indices of human activities (certain since ca. 2400-1800 BC). This article presents the geostatistical predicates, methods (unimodality of realization periods of engraved themes, correlations, seriation, toposeriation, etc.) and principal results on which a first periodization frame has been built
Isotope shifts and hyperfine structure of the Fe I 372 nm resonance line
We report measurements of the isotope shifts of the Fe I resonance line at 372 nm between all four stable
isotopes Fe, Fe, Fe, and Fe, as well as the
complete hyperfine structure of that line for Fe, the only stable
isotope having a non-zero nuclear spin. The field and specific mass shift
coefficients of the transition have been derived from the data, as well as the
experimental value for the hyperfine structure magnetic dipole coupling
constant of the excited state of the transition in Fe: MHz. The measurements were done by means of Doppler-free
laser saturated-absorption spectroscopy in a Fe-Ar hollow cathode using both
natural and enriched iron samples. The measured isotope shifts and hyperfine
constants are reported with uncertainties at the percent level.Comment: 5 pages, 5 figure
Generic Fibrational Induction
This paper provides an induction rule that can be used to prove properties of
data structures whose types are inductive, i.e., are carriers of initial
algebras of functors. Our results are semantic in nature and are inspired by
Hermida and Jacobs' elegant algebraic formulation of induction for polynomial
data types. Our contribution is to derive, under slightly different
assumptions, a sound induction rule that is generic over all inductive types,
polynomial or not. Our induction rule is generic over the kinds of properties
to be proved as well: like Hermida and Jacobs, we work in a general fibrational
setting and so can accommodate very general notions of properties on inductive
types rather than just those of a particular syntactic form. We establish the
soundness of our generic induction rule by reducing induction to iteration. We
then show how our generic induction rule can be instantiated to give induction
rules for the data types of rose trees, finite hereditary sets, and
hyperfunctions. The first of these lies outside the scope of Hermida and
Jacobs' work because it is not polynomial, and as far as we are aware, no
induction rules have been known to exist for the second and third in a general
fibrational framework. Our instantiation for hyperfunctions underscores the
value of working in the general fibrational setting since this data type cannot
be interpreted as a set.Comment: For Special Issue from CSL 201
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