999 research outputs found
Quantum SUSY signatures in low and high energy processes
In the search for phenomenological evidence of supersymmetry through the
indirect method of quantum signatures, it is useful to seek correlations of the
non-standard quantum effects in low and high energy proceses, such as those
involving on one hand the properties of the B-mesons and on the other hand the
physics of the top quark and of the Higgs bosons. There are regions of the MSSM
parameter space where the potential quantum SUSY signatures in the two energy
regimes are strongly interwoven and therefore the eventual detection of these
correlated quantum effects would strongly point towards the existence of
underlying supersymmetric dynamics.Comment: 17 pages, LaTeX, 7 figs included with epsfig. Talk at the 5th
International Workshop on High Energy Physics Phenomenology (WHEPP-5). To
appear in the Proceeding
Production and FCNC decay of supersymmetric Higgs bosons into heavy quarks in the LHC
We analyze the production and subsequent decay of the neutral MSSM Higgs
bosons (h = h^0, H^0, A^0) mediated by flavor changing neutral currents (FCNC)
in the LHC collider. We have computed the h-production cross-section times the
FCNC branching ratio, \sigma(pp -> h -> qq') = \sigma(pp -> h) B(h -> qq'), in
the LHC focusing on the strongly-interacting FCNC sector. Here qq' is an
electrically neutral pair of quarks of different flavors, the dominant modes
being those containing a heavy quark: tc or bs. We determine the maximum
production rates for each of these modes and identify the relevant regions of
the MSSM parameter space, after taking into account the severe restrictions
imposed by low energy FCNC processes. The analysis of \sigma(pp -> h -> qq')
singles out regions of the MSSM parameter space different from those obtained
by maximizing only the branching ratio, due to non-trivial correlations between
the parameters that maximize/minimize each isolated factor. The production
rates for the bs channel can be huge for a FCNC process (0.1-1 pb), but its
detection can be problematic. The production rates for the tc channel are more
modest (10^{-3}-10^{-2} pb), but its detection should be easier due to the
clear-cut top quark signature. A few thousand tc events could be collected in
the highest luminosity phase of the LHC, with no counterpart in the SM.Comment: 25 pages, 9 figures, 2 tables, LaTeX 2e. Typos corrected. Version to
appear in JHE
Fracaso electromecánico inducido por el ejercicio dinámico
Se investiga el fracaso muscular tras la realización de un ejercicio
dinámico de alto esfuerzo, mediante la determinación de índices
cuantitativos de función contráctil. Cincuenta adultos practican
un test triangular en cicloergómetro bajo control ergoespirométrico,
midiendo en el cuádriceps femoral la variación de la
fuerza generada en la estimulación eléctrica (curva fuerzaflrecuencia),
de lafierza máxima voluntaria y del umbral de intensidad
y la cronaxia. Se observan distintos tipos de fatiga de origen
periférico, cuya magnitud no depende de la intensidad del esfuerzo.
La coincidencia del cambio de la fuerza tetánica, de la fuerza
voluntaria y de la cronaxia apoya la responsabilidad del defecto
excitatorio en la fatiga de alta frecuencia, la cual puede causar la
detención del ejercicio. El límite de la aptitud debe referirse a
una capacidad individual según la modificación de diversos parámetros,
entre los cuales debe incluirse una exploración funcional
muscularPeer Reviewe
Heavy charged Higgs boson decaying into top quark in the MSSM
Observing a heavy charged Higgs boson produced in the near future at the
Tevatron or at the LHC would be instant evidence of physics beyond the Standard
Model. Whether such a Higgs boson would be supersymmetric or not it could only
be decided after accurate prediction of its properties. Here we compute the
decay width of the dominant decay of such a boson, namely H^+ -> t \bar{b},
including the leading electroweak corrections originating from large Yukawa
couplings within the MSSM. These electroweak effects turn out to be of
comparable size to the O(alpha_s) QCD corrections in relevant portions of the
MSSM parameter space. Our analysis incorporates the stringent low-energy
constraints imposed by radiative B-meson decays.Comment: 10 pages, LaTeX, 5 figs included as a separate file, full postscript
version available at ftp://ftp.ifae.es/preprint/ft/uabft433.p
Analysis of backgrounds for the ANAIS-112 dark matter experiment
The ANAIS (Annual modulation with NaI(Tl) Scintillators) experiment aims at
the confirmation or refutation of theDAMA/LIBRA positive annual modulation
signal in the low energy detection rate, using the same target and technique,
at the Canfranc Underground Laboratory (LSC) in Spain. ANAIS-112, consisting of
nine 12.5 kg NaI(Tl) modules produced by Alpha Spectra Inc. in a 3x3matrix
configuration, is taking data smoothly in "dark matter search" mode since
August, 2017, after a commissioning phase and operation of the first detectors
during the last years in various setups. A large effort has been carried out
withinANAIS to characterize the background of sodium iodide detectors, before
unblinding the data and performing the first annual modulation analysis. Here,
the background models developed for all the nine ANAIS-112 detectors are
presented. Measured spectra from threshold to high energy in different
conditions are well described by the models based on quantified activities
independently estimated following several approaches. In the region from 1 to 6
keVee the measured, efficiency corrected background level is 3.58+-0.02 keV-1
kg-1 day-1; NaI crystal bulk contamination is the dominant background source
being 210Pb, 40K, 22Na and 3H contributions the most relevant ones. This
background level, added to the achieved 1 keVee analysis threshold (thanks to
the outstanding light collection and robust filtering procedures developed),
allow ANAIS-112 to be sensitive to the modulation amplitude measured by
DAMA/LIBRA, and able to explore at three sigma level in 5 years the WIMP
parameter region singled out by this experiment.Comment: Final version for publicatio
- …