43 research outputs found
Direct Chargino-Neutralino Production at the LHC: Interpreting the Exclusion Limits in the Complex MSSM
We re-assess the exclusion limits on the parameters describing the
supersymmetric (SUSY) electroweak sector of the MSSM obtained from the search
for direct chargino-neutralino production at the LHC. We start from published
limits obtained in simplified models, where for the case of heavy sleptons the
relevant branching ratio, BR(neu2->neu1 Z), is set to one. We show how the
decay mode neu2->neu1 h, which cannot be neglected in any realistic model once
kinematically allowed, substantially reduces the excluded parameter region. We
analyze the dependence of the excluded regions on the phase of the gaugino soft
SUSY-breaking mass parameter, M_1, on the mass of the light scalar tau, on tb
as well as on the squark and slepton mass scales. Large reductions in the
ranges of parameters excluded can be observed in all scenarios. The branching
ratios of charginos and neutralinos are evaluated using a full NLO calculation
for the complex MSSM. The size of the effects of the NLO calculation on the
exclusion bounds is investigated. We furthermore assess the potential reach of
the experimental analyses after collecting 100/fb at the LHC running at 13 TeV.Comment: 34 pages, 12 figures. Minor changes, matches published versio
El control genético de los componentes del rendimiento
No podemos decir que el rendimiento de las plantas esté determinado por todos los genes del organismo, pero sí, que intervienen una gran cantidad, aún algunos que aparentemente no lo afectarían, como por ejemplo, podría ser el color de flor en plantas de polinización entomófíla, donde algunos colores pueden ser más atractivos que otros a los insectos polinizadores y por consiguiente esas plantas podrían producir más semilla, o, genes que en un determinado ambiente no se manifiestan, pero sí lo hacen en presencia de, por ejemplo, una plaga, condición de suelo o de clima particulares. Para poder trabajar con esos caracteres es necesario conocer bien las relaciones que tienen entre sí los componentes del rendimiento. Si la correlación genética entre los mismos es negativa, es decir, seleccionando para aumento de un carácter, disminuimos otro, no conseguiremos progresar en el objetivo final, o sea el rendimiento.Tema: El rendimiento de especies de gran cultivo: características ecofisiológicas y su manipulación genéticaAcademia Nacional de Agronomía y Veterinaria (ANAV
El control genético de los componentes del rendimiento
No podemos decir que el rendimiento de las plantas esté determinado por todos los genes del organismo, pero sí, que intervienen una gran cantidad, aún algunos que aparentemente no lo afectarían, como por ejemplo, podría ser el color de flor en plantas de polinización entomófíla, donde algunos colores pueden ser más atractivos que otros a los insectos polinizadores y por consiguiente esas plantas podrían producir más semilla, o, genes que en un determinado ambiente no se manifiestan, pero sí lo hacen en presencia de, por ejemplo, una plaga, condición de suelo o de clima particulares. Para poder trabajar con esos caracteres es necesario conocer bien las relaciones que tienen entre sí los componentes del rendimiento. Si la correlación genética entre los mismos es negativa, es decir, seleccionando para aumento de un carácter, disminuimos otro, no conseguiremos progresar en el objetivo final, o sea el rendimiento.Tema: El rendimiento de especies de gran cultivo: características ecofisiológicas y su manipulación genéticaAcademia Nacional de Agronomía y Veterinaria (ANAV
Neutralino Decays in the Complex MSSM at One-Loop: a Comparison of On-Shell Renormalization Schemes
We evaluate two-body decay modes of neutralinos in the Minimal Supersymmetric
Standard Model with complex parameters (cMSSM). Assuming heavy scalar quarks we
take into account all two-body decay channels involving charginos, neutralinos,
(scalar) leptons, Higgs bosons and Standard Model gauge bosons. The evaluation
of the decay widths is based on a full one-loop calculation including hard and
soft QED radiation. Of particular phenomenological interest are decays
involving the Lightest Supersymmetric Particle (LSP), i.e. the lightest
neutralino, or a neutral or charged Higgs boson. For the chargino/neutralino
sector we employ two different renormalization schemes, which differ in the
treatment of the complex phases. In the numerical analysis we concentrate on
the decay of the heaviest neutralino and show the results in the two different
schemes. The higher-order corrections of the heaviest neutralino decay widths
involving the LSP can easily reach a level of about 10-15%, while the
corrections to the decays to Higgs bosons are up to 20-30%, translating into
corrections of similar size in the respective branching ratios. The difference
between the two schemes, indicating the size of unknown two-loop corrections,
is less than order(0.1%). These corrections are important for the correct
interpretation of LSP and Higgs production at the LHC and at a future linear
e+e- collider. The results will be implemented into the Fortran code FeynHiggs.Comment: 49 pages, 27 figures, typos corrected. arXiv admin note: substantial
text overlap with arXiv:1112.0760, arXiv:1111.7289, arXiv:1204.400
Separable Subsurface Scattering
In this paper, we propose two real-time models for simulating subsurface scattering for a large variety of translucent materials, which need under 0.5 ms per frame to execute. This makes them a practical option for real-time production scenarios. Current state-of-the-art, real-time approaches simulate subsurface light transport by approximating the radially symmetric non-separable diffusion kernel with a sum of separable Gaussians, which requires multiple (up to 12) 1D convolutions. In this work we relax the requirement of radial symmetry to approximate a 2D diffuse reflectance profile by a single separable kernel. We first show that low-rank approximations based on matrix factorization outperform previous approaches, but they still need several passes to get good results. To solve this, we present two different separable models: the first one yields a high-quality diffusion simulation, while the second one offers an attractive trade-off between physical accuracy and artistic control. Both allow rendering of subsurface scattering using only two 1D convolutions, reducing both execution time and memory consumption, while delivering results comparable to techniques with higher cost. Using our importance-sampling and jittering strategies, only seven samples per pixel are required. Our methods can be implemented as simple post-processing steps without intrusive changes to existing rendering pipelines
Physics Opportunities at mu+mu- Higgs Factories
We update theoretical studies of the physics opportunities presented by
mu+mu- Higgs factories. Interesting measurements of the Standard Model Higgs
decays into {\bar b}b, tau+tau- and WW* may be possible if the Higgs mass is
less than about 160 GeV, as preferred by the precision electroweak data, the
mass range being extended by varying appropriately the beam energy resolution.
A suitable value of the beam energy resolution would also enable the
uncertainty in the b-quark mass to be minimized, facilitating measurements of
parameters in the MSSM at such a first mu+mu- Higgs factory. These measurements
would be sensitive to radiative corrections to the Higgs-fermion-antifermion
decay vertices, which may violate CP. Radiative corrections in the MSSM may
also induce CP violation in Higgs-mass mixing, which can be probed via various
asymmetries measurable using polarized mu+mu- beams. In addition,
Higgs-chargino couplings may be probed at a second mu+mu- Higgs factory.Comment: Report of the Higgs factory working group of the ECFA-CERN study on
Neutrino Factory & Muon Storage Rings at CERN. 28 p
Severe climate change risks to food security and nutrition
This paper discusses severe risks to food security and nutrition that are linked to ongoing and projected climate change, particularly climate and weather extremes in global warming, drought, flooding, and precipitation. We specifically consider the impacts on populations vulnerable to food insecurity and malnutrition due to lower income, lower access to nutritious food, or social discrimination. The paper defines climate-related “severe risk” in the context of food security and nutrition, using a combination of criteria, including the magnitude and likelihood of adverse consequences, the timing of the risk and the ability to reduce the risk. Severe climate change risks to food security and nutrition are those which result, with high likelihood, in pervasive and persistent food insecurity and malnutrition for millions of people, have the potential for cascading effects beyond the food systems, and against which we have limited ability to prevent or fully respond. The paper uses internationally agreed definitions of risks to food security and nutrition to describe the magnitude of adverse consequences. Moreover, the paper assesses the conditions under which climate change-induced risks to food security and nutrition could become severe based on findings in the literature using different climate change scenarios and shared socioeconomic pathways. Finally, the paper proposes adaptation options, including institutional management and governance actions, that could be taken now to prevent or reduce the severe climate risks to future human food security and nutrition
HI Velocity Fields and Rotation Curves
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