5,088 research outputs found
Probing the spin-parity of the Higgs boson via jet kinematics in vector boson fusion
Determining the spin and the parity quantum numbers of the recently
discovered Higgs-like boson at the LHC is a matter of great importance. In this
paper, we consider the possibility of using the kinematics of the tagging jets
in Higgs production via the vector boson fusion (VBF) process to test the
tensor structure of the Higgs-vector boson () interaction and to determine
the spin and CP properties of the observed resonance. We show that an anomalous
vertex, in particular its explicit momentum dependence, drastically
affects the rapidity between the two scattered quarks and their transverse
momenta and, hence, the acceptance of the kinematical cuts that allow to select
the VBF topology. The sensitivity of these observables to different spin-parity
assignments, including the dependence on the LHC center of mass energy, are
evaluated. In addition, we show that in associated Higgs production with a
vector boson some kinematical variables, such as the invariant mass of the
system and the transverse momenta of the two bosons and their separation in
rapidity, are also sensitive to the spin--parity assignments of the Higgs--like
boson.Comment: 15 pages, 5 figure
Azimuthal Angle Probe of Anomalous HWW Couplings at the LHeC
A high energy ep collider, such as the proposed LHeC, possesses the unique
facility of permitting direct measurement of the HWW coupling without
contamination from the HZZ coupling. At such a machine, the fusion of two W
bosons through the HWW vertex would give rise to typical charged current (CC)
events accompanied by a Higgs boson. We demonstrate that azimuthal angle
correlations between the observable CC final states could then be a sensitive
probe of the nature of the HWW vertex and hence of the CP properties of the
Higgs boson.Comment: Revised version to appear in Physical Review Letters, some typos and
mis-labellings corrected, references reorganised and update
Normalizing Weak Boson Pair Production at the Large Hadron Collider
The production of two weak bosons at the Large Hadron Collider will be one of
the most important sources of SM backgrounds for final states with multiple
leptons. In this paper we consider several quantities that can help normalize
the production of weak boson pairs. Ratios of inclusive cross-sections for
production of two weak bosons and Drell-Yan are investigated and the
corresponding theoretical errors are evaluated. The possibility of predicting
the jet veto survival probability of VV production from Drell-Yan data is also
considered. Overall, the theoretical errors on all quantities remain less than
5-20%. The dependence of these quantities on the center of mass energy of the
proton-proton collision is also studied.Comment: 11 pages; added references, minor text revisions, version to appear
in Phys. Rev.
A comparative study of the electrochemical properties of vitamin B-6 related compounds at physiological pH
A comparative study of vitamin B6 group and related compounds in buffered solutions using electrochemical techniques has been performed at neutral pH. Irreversible bi- or tetra-electronic processes are observed for these substances, and the electron transfer coefficient (αn) calculated. It was concluded that either the first or second electron transfer were the rate determining step of the electrode process. The diffusion coefficient of these substances was calculated and the values given follow an inverse tendency to the molecular size. For aldehydes the values obtained were corrected of the hydration reaction.
It is important to remark that catalytic waves were reported for the first time for these compounds. Using a model involving the nitrogen of the basic structure the kinetic constants were calculated for most of them
The role of cognitive individual differences in digital versus pen-and-paper writing
It is unknown whether and to what extent cognitive individual differences may play different roles in paper versus computer-based second language (L2) writing. This exploratory study is a first attempt to explore this issue, focusing on the effects of working memory and language aptitude on the quality of paper versus computer-based L2 writing performance. Forty-two Spanish learners of L2 English performed a problem-solving task either digitally or on paper, took a working memory n-back test, and completed LLAMA tests to measure language aptitude. The quality of their L2 written texts was assessed in terms of complexity, accuracy and fluency (CAF) measures. The results indicated that the role of cognitive individual differences may vary depending on the writing environment
Estimating turbulence kinetic energy dissipation rates in numerically simulated stratocumulus cloud-top and convective boundary layer flow: Evaluation of different methods.
We perform analysis of direct numerical simulation (DNS) data of two flow cases: stratocumulus cloud-top (SCT) and convective boundary layer (CBL). We test different methods for turbulence kinetic energy dissipation rate (EDR) retrieval. Among others we investigate performance of a new, iterative method, proposed recently in Wacławczyk et al. (2017), where an analytical model for energy spectra in the dissipative range is needed. We argue, the new method has some advantages over the standard spectral retrieval techniques. To apply it, only the information on the signals’ cut-off wavelength is needed and it is not necessary to define the fitting range in the inertial part of the spectrum. With this, the new method could be a basis of a general algorithm for EDR retrieval, applicable to a wide range of different atmospheric data (e.g. from commercial aircrafts). Moreover, we investigate how the presence of anisotropy due to shear, buoyancy and external intermittency in the flow affects the EDR retrieval based on the classical K41 for isotropic turbulence (Kolmogorov, 1941). © 2019 International Symposium on Turbulence and Shear Flow Phenomena, TSFP. All rights reserved
La dimensión afectiva olvidada del conocimiento didáctico del contenido de los profesores de ciencias
Shulman se refería al paradigma olvidado de la investigación sobre el profesor el que no se hubiese considerado el contenido de la materia específica, lo que le llevó a desarrollar el Conocimiento Didáctico del Contenido (CDC). Sin embargo la dimensión afectiva y emocional podemos considerarla la parte olvidada del CDC. Shulman consideraba que el CDC es una forma de razonamiento y de acción didáctica por medio de la cual los profesores transforman el contenido en representaciones comprensibles a los estudiantes. Investigaciones recientes indican que no hay acción humana, sin una emoción que la haga posible. Desde esta perspectiva es indudable que las emociones del profesor formarían parte del CDC. En el simposio mostraremos la relación entre lo cognitivo y lo afectivo del profesor y la necesidad de incluir la dimensión afectiva en el CDC de los profesores de ciencias
Probing the role of point mutations in the cyp51A gene from Aspergillus fumigatus in the model yeast Saccharomyces cerevisiae
Azole-resistant strains of Aspergillus fumigatus have been detected and the underlying molecular mechanisms of resistance characterized. Point mutations in the cyp51A gene have been proved to be related to azole resistance in A. fumigatus clinical strains and with different resistance profiles depending on the amino acid change (G54E, G54V, G54R, G54W, M220V, M220K, M220T, M220I). The aim of this work was to express A. fumigatus cyp51A genes in the yeast Saccharomyces cerevisiae in order to better assess the contribution of each independent amino acid substitution to resistance. A tetracycline regulatable system allowing repression of the endogenous essential ERG11 gene was used. The expression of Aspergillus cyp51A alleles could efficiently restore the absence of ERG11 in S. cerevisiae. In general, S. cerevisiae clones expressing. A. fumigatus cyp51A alleles from azole-resistant isolates showed higher MICs to all azoles tested than those expressing alleles from susceptible isolates. The azole susceptibility profiles obtained in S. cerevisiae upon expression of specific cyp51A alleles recapitulated susceptibility profiles observed from their A. fumigatus origins. In conclusion this work supports the concept that characteristics of specific A. fumigatus cyp51A alleles could be investigated in the heterologous host S. cerevisia
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