Photoinduced Floquet topological magnons in Kitaev magnets

We study periodically driven pure Kitaev model and ferromagnetic phase of the Kitaev-Heisenberg model on the honeycomb lattice by off-resonant linearly and circularly-polarized lights at zero magnetic field. Using a combination of linear spin wave and Floquet theories, we show that the effective time-independent Hamiltonians in the off-resonant regime map onto the corresponding anisotropic static spin model, plus a tunable photoinduced magnetic field along the $[111]$ direction, which precipitates Floquet topological magnons and chiral magnon edge modes. They are tunable by the light amplitude and polarization. Similarly, we show that the thermal Hall effect induced by the Berry curvature of the Floquet topological magnons can also be tuned by the laser field. Our results pave the way for ultrafast manipulation of topological magnons in irradiated Kitaev magnets, and could play a pivotal role in the investigation of ultrafast magnon spin current generation in Kitaev materials.Comment: 7 pages, 5 figures + Supplemental Materia

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 ($HVV$) interaction and to determine the spin and CP properties of the observed resonance. We show that an anomalous $HVV$ 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

Driving factors for school milk demand in Germany

School milk consumption has declined steadily in Germany. A research project was set up to retrieve quantifiable information on the different factors of influence and to develop solutions to improve the school milk consumption.. The main goal is to evaluate the impact of price, product range, distribution form, information campaigns, regional situation, county based social index, socially-funded school milk distribution, and gender shares, as well as the immigration background share within a class. A total of 400 primary schools were selected by stratified random sampling. Surveys for principals and school milk managers were used to gain information on distribution problems throughout the milk chain, on the handling, and their attitudes towards school milk and milk in general. The price of school milk is being reduced stepwise in the 2008/09 school year. The quantity of consumption is reported per class. A multilevel analysis is applied to determine the factors driving consumption at the class level. First results will be validated. The paper comprises an extended introduction, followed by the research approach. A descriptive analysis is given following a detailed description of the experiment.. The estimation procedure is discussed before the results are presented. Finally, a qualification of outcomes and conclusions concerning further research are found.School Milk, Demand Subsidy, Food Demand, Multilevel Analysis., Agricultural and Food Policy, Food Consumption/Nutrition/Food Safety,

On the non-monotonic variation of the entrainment buoyancy flux with wind shear

The magnitude of the entrainment buoyancy flux, and hence the growth rate of the convective boundary layer, does not increase monotonically with wind shear. Explanations for this have previously been based on wind-shear effects on the turbulence kinetic energy. By distinguishing between turbulent and non-turbulent regions, we provide an alternative explanation based on two competing wind-shear effects: the initial decrease in the correlation between buoyancy and vertical velocity fluctuations, and the increase in the turbulent area fraction. The former is determined by the change in the dominant forcing; without wind shear, buoyancy fluctuations drive vertical velocity fluctuations and the two are thus highly correlated; with wind shear, vertical velocity fluctuations are partly determined by horizontal velocity fluctuations via the transfer of kinetic energy through the pressure-strain correlation, thus reducing their correlation with the buoyancy field. The increasing turbulent area fraction, on the other hand, is determined by the increasing shear production of turbulence kinetic energy inside the entrainment zone. We also show that the dependence of these conditional statistics on the boundary-layer depth and on the magnitude of the wind shear can be captured by a single non-dimensional variable, which can be interpreted as an entrainment-zone Froude number

Charge Smoothening and Band Flattening due to Hartree corrections in Twisted Bilayer Graphene

Doping twisted bilayer graphene away from charge neutrality leads to an enormous buildup of charge inhomogeneities within each Moir\'{e} unit cell. Here we show, using unbiased real-space self-consistent Hartree calculations on a relaxed lattice, that Coulomb interactions smoothen this charge imbalance by changing the occupation of earlier identified `ring' orbitals in the AB/BA region and `center' orbitals at the AA region. For hole doping, this implies an increase of the energy of the states at the ${\bf \Gamma}$ point, leading to a further flattening of the flat bands and a pinning of the Van Hove singularity at the Fermi level. The charge smoothening will affect the subtle competition between different possible correlated phases.Comment: 6 pages, 5 figure

Extraction of Top Backgrounds in the Higgs Boson Search with the H→WW∗→ℓℓ+ETmissH\to WW^\ast \to \ell\ell + E_{\rm T}^{\rm miss} Decay with a Full-Jet Veto at the LHC

The search for a Standard Model Higgs boson with the $H\to WW^\ast\to \ell\ell + E_{\rm T}^{\rm miss}$ decay and the application of a full-jet veto yields a strong sensitivity in the mass range $130<m_H<200$ GeV. One of the residual backgrounds is related to processes involving top quarks. A method for the extraction of top backgrounds is evaluated at the parton and hadronic levels based on the data-driven extraction of the jet veto survival probability. The uncertainty of the proposed method is about 15%.Comment: 7 pages, 4 tables, v3 fixes a macro issue in the metadata, published version 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

Enfoque a los principales procedimientos en el D. E. M.

97 p.Como la incorporación del Departamento de Educación a la gestión municipal es muy reciente ,adolece - como es lógico - de algún grado de improvisación entre sus procedimientos, no llegando aún a estructurarse dentro de su Administración una total complementación con los principios básicos de control que rigen a los Municipios. Es por este motivo que parece ser un organismo total y absolutamente autónomo, cuando en la realidad es y debe ser parte integral de todo el quehacer municipal. Viendo que un poco las cosas se hacen " de memoria”, este trabajo pretende ser un primer paso para insertar dentro de los municipios un Sistema de Cursogramas tendiente a agilizar el desarrollo de los procedimientos internos y simplificar la exposición de tales operaciones ante posibles fiscalizaciones por intermedio del Ministerio del interior o de Contraloría General de la República, ya que representan una fotografía del Sistema de Control Interno que debe estar guiado al resguardo eficiente de los recursos del Estado. Mayor importancia adquiere esta idea si consideramos que el Sistema de Cursogramas a través del Departamento de Educación puede ser útil para todos los innumerables procedimientos municipales, y así no dejar a las Unidades de Control trabajando en base a eventuales aciertos o errores administrativos, sin haber dado la pauta que guíe las operaciones, para poder, efectivamente, ser ella un control de controles como teórica y prácticamente debe trabajar una Unidad de Control o Auditoria interna