121 research outputs found
Stop Decay with LSP Gravitino in the final state:
In MSSM scenarios where the gravitino is the lightest supersymmetric particle
(LSP), and therefore a viable dark matter candidate, the stop
could be the next-to-lightest superpartner (NLSP). For a mass spectrum
satisfying: ,
the stop decay is dominated by the 3-body mode . We calculate the stop life-time, including the full
contributions from top, sbottom and chargino as intermediate states. We also
evaluate the stop lifetime for the case when the gravitino can be approximated
by the goldstino state. Our analytical results are conveniently expressed using
an expansion in terms of the intermediate state mass, which helps to identify
the massless limit.
In the region of low gravitino mass ()
the results obtained using the gravitino and goldstino cases turns out to be
similar, as expected. However for higher gravitino masses the results for the lifetime could show a difference
of O(100)\%
Dark Left-Right Gauge Model: SU(2)_R Phenomenology
In the recently proposed dark left-right gauge model of particle
interactions, the left-handed fermion doublet is connected to its
right-handed counterpart through a scalar bidoublet, but
couples to only through which has no vacuum expectation value.
The usual R parity, i.e. , can be defined for this
nonsupersymmetric model so that both and are odd together with
. The lightest is thus a viable dark-matter candidate (scotino).
Here we explore the phenomenology associated with the gauge group of
this model, which allows it to appear at the TeV energy scale. The exciting
possibility of charged leptons is discussed.Comment: 12 pages, 2 figure
Slim SUSY
he new SM-like Higgs boson discovered recently at the LHC, with mass mh≃125GeV, as well as the direct LHC bounds on the mass of superpartners, which are entering into the TeV range, suggest that the minimal surviving supersymmetric extension of the SM (MSSM), should be characterized by a heavy SUSY-breaking scale. Several variants of the MSSM have been proposed to account for this result, which vary according to the accepted degree of fine-tuning. We propose an alternative scenario here, Slim SUSY, which contains sfermions with multi-TeV masses and gauginos/higgsinos near the EW scale, but it includes the heavy MSSM Higgs bosons (H0, A0, H±) near the EW scale too. We discuss first the formulation and constraints of the Slim SUSY scenario, and then identify distinctive heavy Higgs signals that could be searched at the LHC, within scenarios with the minimal number of superpartners with masses near the EW scale.Instituto de Física La PlataConsejo Nacional de Investigaciones Científicas y Técnica
Slim SUSY
he new SM-like Higgs boson discovered recently at the LHC, with mass mh≃125GeV, as well as the direct LHC bounds on the mass of superpartners, which are entering into the TeV range, suggest that the minimal surviving supersymmetric extension of the SM (MSSM), should be characterized by a heavy SUSY-breaking scale. Several variants of the MSSM have been proposed to account for this result, which vary according to the accepted degree of fine-tuning. We propose an alternative scenario here, Slim SUSY, which contains sfermions with multi-TeV masses and gauginos/higgsinos near the EW scale, but it includes the heavy MSSM Higgs bosons (H0, A0, H±) near the EW scale too. We discuss first the formulation and constraints of the Slim SUSY scenario, and then identify distinctive heavy Higgs signals that could be searched at the LHC, within scenarios with the minimal number of superpartners with masses near the EW scale.Instituto de Física La PlataConsejo Nacional de Investigaciones Científicas y Técnica
Impact of DM direct searches and the LHC analyses on branon phenomenology
Dark Matter direct detection experiments are able to exclude interesting
parameter space regions of particle models which predict an important amount of
thermal relics. We use recent data to constrain the branon model and to compute
the region that is favored by CDMS measurements. Within this work, we also
update present colliders constraints with new studies coming from the LHC.
Despite the present low luminosity, it is remarkable that for heavy branons,
CMS and ATLAS measurements are already more constraining than previous analyses
performed with TEVATRON and LEP data.Comment: 17 pages, 2 figure
Detection of Neutral MSSM Higgs Bosons at LEP-II and NLC
We study the possibility of detecting the neutral Higgs bosons predicted in
the Minimal Supersymmetric Standard Model (h0, H0, A0), with the reactions e+
e- --> b b h0 (H0, A0), using the helicity formalism. We analyze the region of
parameter space (m_A0-tan beta) where h0(H0, A0) could be detected in the limit
when tan beta is large. The numerical computation is done for the energy which
is expected to be available at LEP-II (sqrt{s} = 200 GeV) and for a possible
Next Linear e+ e- Collider (sqrt{s}=500 GeV).Comment: To be published in Phys.Rev.
Use of healthcare REsources and associated COsts in controlled versus uncontrolled carcinoid SYndrome in patients with neuroendocrine tumours: the RECOSY study
Purpose: To report healthcare resource use and associated costs in controlled versus uncontrolled carcinoid syndrome (CS) in patients with neuroendocrine tumours. Methods: A cross-sectional, non-interventional multicentre study was conducted with retrospective data analysis. Resource use was compared between two patient groups: those with controlled CS (> 12 months with no uncontrolled CS episodes) and uncontrolled CS (< 12 months since last uncontrolled episode). Patients were matched for age, sex, and origin and grade of tumour. When no matching patients were available, data from deceased patients were used. Information on healthcare resource use came from review of medical records, patient history and physician reports. Working capacity was assessed using the Work Productivity and Activity Impairment General Health questionnaire. Results: Twenty-six university hospitals in Spain participated, between July 2017 and April 2018. 137 patients were enrolled; 104 were analysed (2 groups of 52). Patients with uncontrolled CS had 10 times more emergency department (ED) visits (mean 1.0 vs 0.10 visits; P = 0.0167), were more likely to have a hospital admission (40.4% vs 19.2%; P = 0.0116) and had longer hospital stays (mean 7.87 vs 2.10 days; P = 0.0178) than those with controlled CS. This corresponded to higher annual hospitalisation costs (mean €5511.59 vs €1457.22; P = 0.028) and ED costs (€161.25 vs €14.85; P = 0.0236). The mean annual total healthcare costs were 60.0% higher in patients with uncontrolled than controlled CS (P = NS). Conclusion: This study quantifies higher health resource use, and higher hospitalisation and ED costs in patients with uncontrolled CS. Better control of CS may result 3in lower medical costs
Three generations of Higgses and the cyclic groups
Multi Higgs doublet models are interesting extensions of the Standard Model
that can be related to flavor. The reason is that most flavor models usually
involve the presence of several additional scalar fields. In this work we
present an analysis that shows that for renormalizable flavor models based on
the cyclic group of order , if there is one flavored SU(2) double Higgs per
generation, the smallest that can be used to reproduce the
Nearest-Neighbor-Interaction texture for the quark mass matrices is N=5.
Results for the Higgs spectrum and consistency under mixing in a
specific model with are also presented.Comment: 10 pages, details on the discussion of KK mixing added, one appendix
with the discussion of N even added, references added. Version to appear in
Phys. Lett.
Declaración de Cancún: declaración internacional de Cancún sobre el derecho a la nutrición en los hospitales
La declaración de Cancún por el derecho humano de los enfermos a recibir una terapia nutricional oportuna y óptima en cualquier lugar donde se encuentren ha sido emitida por los Presidentes de las Sociedades y Asociaciones de Nutrición Clínica y Terapia Nutricional de América Latina y el Caribe, en el marco del XI Congreso de FELANPE/XV Congreso de AMAEE, en la Ciudad de Cancún Quintana Roo, México, el día 20 de mayo de 2008
Characterization of the Atmospheric Muon Flux in IceCube
Muons produced in atmospheric cosmic ray showers account for the by far
dominant part of the event yield in large-volume underground particle
detectors. The IceCube detector, with an instrumented volume of about a cubic
kilometer, has the potential to conduct unique investigations on atmospheric
muons by exploiting the large collection area and the possibility to track
particles over a long distance. Through detailed reconstruction of energy
deposition along the tracks, the characteristics of muon bundles can be
quantified, and individual particles of exceptionally high energy identified.
The data can then be used to constrain the cosmic ray primary flux and the
contribution to atmospheric lepton fluxes from prompt decays of short-lived
hadrons.
In this paper, techniques for the extraction of physical measurements from
atmospheric muon events are described and first results are presented. The
multiplicity spectrum of TeV muons in cosmic ray air showers for primaries in
the energy range from the knee to the ankle is derived and found to be
consistent with recent results from surface detectors. The single muon energy
spectrum is determined up to PeV energies and shows a clear indication for the
emergence of a distinct spectral component from prompt decays of short-lived
hadrons. The magnitude of the prompt flux, which should include a substantial
contribution from light vector meson di-muon decays, is consistent with current
theoretical predictions.Comment: 36 pages, 39 figure
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