976 research outputs found
H^+H^- Pair Production at the Large Hadron Collider
We study the pair production of charged Higgs bosons at the CERN Large Hadron
Collider in the context of the minimal supersymmetric extension of the standard
model. We compare the contributions due to qq-bar annihilation at the tree
level and gg fusion, which proceeds at one loop. At small or large values of
tan(beta), H^+H^- production proceeds dominantly via bb-bar annihilation, due
to Feynman diagrams involving neutral CP-even Higgs bosons and top quarks,
which come in addition to the usually considered Drell-Yan diagrams. In the
case of gg fusion, the squark loop contributions may considerably enhance the
well-known quark loop contributions.Comment: 15 pages (Latex), 4 figures (Postscript
CP Violation Induced by Heavy Majorana Neutrinos in the Decays of Higgs Scalars into Top-Quark, W- and Z-Boson Pairs
We analyze the possibility of violation induced by heavy Majorana
neutrinos in the decays of the Higgs particle into top-quark, - and
-boson pairs. In the framework of various ``see-saw" models with interfamily
mixings, we find that Majorana neutrinos may give rise to sizable -odd
observables at the one-loop electroweak order. Numerical estimates of these
-violating effects that may be detected in high-energy colliders are
presented.Comment: 16 p. (1 Figure), LaTeX, MAD/PH/78
Rice-fish research and development in Asia
Joint proceedings of two international workshops on rice-fish farming systems research and development û one held in Ubon, Thailand, on 23-27 October 1988; and the other on 23-27 October 1989 in Nueva Ecija, Philippines; gathering country overviews, production systems, economic and biological interactions, research and extension programs, and on-station and on-farm research activities from Bangladesh, China, India, Indonesia, Korea, Malaysia, the Philippines, Thailand and Vietnam.Rice-fish culture, Integrated farming, Conferences, Asia,
FCNC Top Quark Decays in Extra Dimensions
The flavor changing neutral top quark decay t -> c X is computed, where X is
a neutral standard model particle, in a extended model with a single extra
dimension. The cases for the photon, X= \gammaR_\xi gauge. We find that
the branching ratios can be enhanced by the dynamics originated in the extra
dimension. In the limit where 1/R >> ->, we have found Br(t -> c \gamma) \simeq
10^{-10} for 1/R = 0.5 TeV. For the decay t -> c H, we have found Br(t -> cH)
\simeq 10^{-10} for a low Higgs mass value. The branching ratios go to zero
when 1/R -> \infty.Comment: Accepted to be published in the Europ. Phys. Jour. C; 16 pages, 2
figure
Seminal magnetic fields from Inflato-electromagnetic Inflation
We extend some previous attempts to explain the origin and evolution of
primordial magnetic fields during inflation induced from a 5D vacuum. We show
that the usual quantum fluctuations of a generalized 5D electromagnetic field
cannot provide us with the desired magnetic seeds. We show that special fields
without propagation on the extra non-compact dimension are needed to arrive to
appreciable magnetic strengths. We also identify a new magnetic tensor field
in this kind of extra dimensional theories. Our results are in very
good agreement with observational requirements, in particular from TeV Blazars
and CMB radiation limits we obtain that primordial cosmological magnetic fields
should be close scale invariance.Comment: Improved version. arXiv admin note: text overlap with arXiv:1007.3891
by other author
Electroweak Corrections to the Charged Higgs Boson Decay into Chargino and Neutralino
The electroweak corrections to the partial widths of the decays including one-loop
diagrams of the third generation quarks and squarks, are investigated within
the Supersymmetric Standard Model. The relative corrections can reach the
values about 10%, therefore they should be taken into account for the precise
experimental measurement at future colliders.Comment: 21 pages, 6 eps figures, 1 Latex fil
Trapping of two-component matter-wave solitons by mismatched optical lattices
We consider a one-dimensional model of a two-component Bose-Einstein
condensate in the presence of periodic external potentials of opposite signs,
acting on the two species. The interaction between the species is attractive,
while intra-species interactions may be attractive too [the system of the
right-bright (BB) type], or of opposite signs in the two components [the
gap-bright (GB) model]. We identify the existence and stability domains for
soliton complexes of the BB and GB types. The evolution of unstable solitons
leads to the establishment of oscillatory states. The increase of the strength
of the nonlinear attraction between the species results in symbiotic
stabilization of the complexes, despite the fact that one component is centered
around a local maximum of the respective periodic potential
Avances en el estudio de las bases genéticas y organolépticas del cacao fino o de aroma en el Perú
Las variedades de cacao fino o de aroma en el Perú son utilizados para elaborar los mejores chocolates del
mundo por sus exquisitas y poco comunes características organolépticas, Estas características permiten que
el cacao peruano gane reconocimiento internacional y de ahí su gran valor económico. A pesar de esto,
poco se sabe sobre los componentes genéticos y/o ambientales que contribuyen a la exclusividad de este
valioso recurso económico. En el proyecto de investigación aplicada: “Estudio molecular de la diversidad
genética de los cacaos aromáticos en el Perú con fines del fortalecimiento de su competitividad y aumento
de la producción nacional de cacao de calidad”, financiado por Innóvate Perú del Ministerio de la
Producción, se tiene como objetivos determinar la variabilidad genética y caracterización organoléptica de
más de 100 tipos de cacao fino o de aroma que se cultivan a lo largo de las cinco principales regiones del
Perú (Amazonas, Cusco, San Martin, Piura y Huánuco). Adicionalmente, la Universidad Nacional Agraria
de la Selva en Tingo María y el Instituto de Investigaciones de la Amazonia Peruana en Tarapoto,
hospedarán bancos de germoplasma y de propagación de esquejes para la difusión y estudios de estos
valiosos recursos. Hasta inicios del 2017, ya se han recolectado más de 80 genotipos provenientes de las
cinco regiones. Protocolos para análisis sensoriales que cumplan los más rigurosos estándares
internacionales se han venido estableciendo. Por otro lado, técnicas de marcadores moleculares usando
marcadores de DNA tipo SSR y SNPs, seguido por secuenciamiento de ADN, se vienen estableciendo.
Estudios de asociación de fenotipo-genotipo formarán parte del conocimiento generado en este proyecto.
Adicionalmente, estos conocimientos permitirán generar información genómica valiosa para salvaguardar
nuestra biodiversidad nativa, otorgándole a los productores y sus asociaciones de herramientas para
proteger sus recursos genéticos y a los potenciales mejoradores de cacao más luces en cuanto a la asociación
genotipo-calidad. Se espera que a fin del proyecto, se cuente con los resultados de genotipificación de más
de 100 genotipos de cacao fino o de aroma y mediante el resecuenciamiento se revelen SNPs particulares
para cada grupo genético en cada región muestreada
Single Top Production as a Window to Physics Beyond the Standard Model
Production of single top quarks at a high energy hadron collider is studied
as a means to identify physics beyond the standard model related to the
electroweak symmetry breaking. The sensitivity of the -channel mode,
the -channel -gluon fusion mode, and the \tw mode to various possible
forms of new physics is assessed, and it is found that the three modes are
sensitive to different forms of new physics, indicating that they provide
complimentary information about the properties of the top quark. Polarization
observables are also considered, and found to provide potentially useful
information about the structure of the interactions of top.Comment: References added and minor discussion improvements; results
unchanged; Version to be published in PR
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