116 research outputs found
violation in minimal supersymmetric standard model
violating phenomena predicted by the minimal supersymmetric standard
model are discussed in a case where the violating phases in SUSY sector
are not suppressed. The electric dipole moments of the neutron and the electron
are large, but can be smaller than their experimental upper bounds if the
scalar quarks and leptons are heavier than a few TeV. violating asymmetries
in the production processes of the different neutralino pair and the different
chargino pair emerge at the tree level. They could be as large as of order
in unpolarized electron beam experiments and in polarized
electron beam experiments. In a pair production of the charginos of the same
mass, the asymmetry emerges through the electric and the weak "electric" dipole
moments of the charginos at the loop level, but its magnitude is at most of
order .Comment: 7 pages with 7 figures, TKU-HEP 94/02; IFM 2/94, LaTeX with Elsevir
Science Publisher's style file, espcrc2.sty. (To appear in the proceedings of
the Third KEK Topical Conference on CP Violation, November 1993) Figures are
not included. The complete PostScript file can be obtained by anonymous ftp
from ape.sp.u-tokai.ac.jp in the directr
Causes of endemic radiation in the Caribbean: evidence from the historical biogeography and diversification of the butterfly genus Calisto(Nymphalidae: Satyrinae: Satyrini)
BACKGROUND: Calisto is the largest butterfly genus in the West Indies but its systematics, historical biogeography and the causes of its diversification have not been previously rigorously evaluated. Several studies attempting to explain the wide-ranging diversity of Calisto gave different weights to vicariance, dispersal and adaptive radiation. We utilized molecular phylogenetic approaches and secondary calibrations points to estimate lineage ages. In addition, we used the dispersal-extinction-cladogenesis model and Caribbean paleogeographical information to reconstruct ancestral geographical distributions. We also evaluated different models of diversification to estimate the dynamics of lineage radiation within Calisto. By understanding the evolution of Calisto butterflies, we attempt to identify the main processes acting on insular insect diversity and the causes of its origin and its maintenance. RESULTS: The crown age of Calisto was estimated to the early Oligocene (31 ± 5 Ma), and a single shift in diversification rate following a diversity-dependent speciation process was the best explanation for the present-day diversity found within the genus. A major increase in diversification rate was recovered at 14 Ma, following geological arrangements that favoured the availability of empty niches. Inferred ancestral distributional ranges suggested that the origin of extant Calisto is in agreement with a vicariant model and the origin of the Cuban lineage was likely the result of vicariance caused by the Cuba-Hispaniola split. A long-distance dispersal was the best explanation for the colonization of Jamaica and the Bahamas. CONCLUSIONS: The ancestral geographical distribution of Calisto is in line with the paleogeographical model of Caribbean colonization, which favours island-to-island vicariance. Because the sister lineage of Calisto remains ambiguous, its arrival to the West Indies remains to be explained, although, given its age and historical biogeography, the hypothesized GAARlandia land bridge might have been a plausible introduction route from continental America. Intra-island radiation caused by ecological innovation and the abiotic creation of niche spaces was found to be the main force shaping Calisto diversity and island endemism in Hispaniola and Cuba. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12862-014-0199-7) contains supplementary material, which is available to authorized users
Implicit Regularization and Renormalization of QCD
We apply the Implicit Regularization Technique (IR) in a non-abelian gauge
theory. We show that IR preserves gauge symmetry as encoded in relations
between the renormalizations constants required by the Slavnov-Taylor
identities at the one loop level of QCD. Moreover, we show that the technique
handles divergencies in massive and massless QFT on equal footing.Comment: (11 pages, 2 figures
Lepton flavor violation in the Simplest Little Higgs model
The flavor sector of Little Higgs models based on product groups, notably the
Littlest Higgs with T parity (LHT), has been extensively studied and some
amount of fine tuning was found to be required to meet the experimental
constraints. However, no such attention has been paid to other classes of
models. Here we analyze the phenomenology of flavor mixing in the lepton sector
of a simple group model, the Simplest Little Higgs (SLH). We obtain the Feynman
rules of the SLH in the 't Hooft-Feynman gauge up to the necessary order and
calculate the leading contributions to the rare processes mu -> e gamma, mu ->
eee and mu-e conversion in nuclei. We find results comparable to those of the
LHT model, because in both cases they arise at the one-loop level. These
require the flavor alignment of the Yukawa couplings of light and heavy leptons
at the per cent level or an effective scale of around 10 TeV.Comment: 41 pages, 8 figures; minor changes and one reference added, version
to appear in JHE
Muon to electron conversion in the Littlest Higgs model with T-parity
Little Higgs models provide a natural explanation of the little hierarchy
between the electroweak scale and a few TeV scale, where new physics is
expected. Under the same inspiring naturalness arguments, this work completes a
previous study on lepton flavor-changing processes in the Littlest Higgs model
with T-parity exploring the channel that will eventually turn out to be the
most sensitive, \mu-e conversion in nuclei. All one-loop contributions are
carefully taken into account, results for the most relevant nuclei are provided
and a discussion of the influence of the quark mixing is included. The results
for the Ti nucleus are in good agreement with earlier work by Blanke et al.,
where a degenerate mirror quark sector was assumed. The conclusion is that,
although this particular model reduces the tension with electroweak precision
tests, if the restrictions on the parameter space derived from lepton flavor
violation are taken seriously, the degree of fine tuning necessary to meet
these constraints also disfavors this model.Comment: 26 pages, 7 figures, 4 tables; discussion improved, results
unchanged, one reference added, version to appear in JHE
Por Doña Elvira Salvago, viuda de D. Ioseph Chinchilla, vezina de Malaga, con D. Juan Thomas Salvago, vezino de dicha ciudad, y D. Ioseph Salvago, vezino de la de Ronda, sobre la possession de el vinculo, y mayorazgo que fundò D. Alonso Gamero, y Doña Beatriz Ximenez su muger
Fecha aproximada de imp. deducida del resto de docs. con los que forma volumenTexto a dos col.Inic. grabPrecede al tít.: "Jesus, Maria, y Joseph"1342514v-5A-E
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