Ogus realization of 1-motives

After introducing the Ogus realization of 1-motives we prove that it is a fully faithful functor. More precisely, following a framework introduced by Ogus, considering an enriched structure on the de Rham realization of 1-motives over a number field, we show that it yields a full functor by making use of an algebraicity theorem of Bost

Method to measure off-axis displacements based on the analysis of the intensity distribution of a vortex beam

We study the properties of the Fraunhofer diffraction patterns produced by Gaussian beams crossing spiral phase plates. We show, both analytically and numerically, that off-axis displacements of the input beam produce asymmetric diffraction patterns. The intensity profile along the direction of maximum asymmetry shows two different peaks. We find that the intensity ratio between these two peaks decreases exponentially with the off-axis displacement of the incident beam, the decay being steeper for higher strengths of the optical singularity of the spiral phase plate. We analyze how this intensity ratio can be used to measure small misalignments of the input beam with a very high precision.Comment: 8 pages, 4 figures. Accepted for publication in PR

Novel spectral kurtosis technology for adaptive vibration condition monitoring of multi-stage gearboxes

In this paper, the novel wavelet spectral kurtosis (WSK) technique is applied for the early diagnosis of gear tooth faults. Two variants of the wavelet spectral kurtosis technique, called variable resolution WSK and constant resolution WSK, are considered for the diagnosis of pitting gear faults. The gear residual signal, obtained by filtering the gear mesh frequencies, is used as the input to the SK algorithm. The advantages of using the wavelet-based SK techniques when compared to classical Fourier transform (FT)-based SK is confirmed by estimating the toothwise Fisher's criterion of diagnostic features. The final diagnosis decision is made by a three-stage decision-making technique based on the weighted majority rule. The probability of the correct diagnosis is estimated for each SK technique for comparison. An experimental study is presented in detail to test the performance of the wavelet spectral kurtosis techniques and the decision-making technique

Dairy production in urban and periurban area of Extrême-Nord in Cameroon: milk yield and microbial contamination

Local dairy production plays a very important role in developing countries in order to promote the health status of the population. To determine the weight and the hygiene level of milk products, available in the market of the capital city of the Extrême-Nord region, a survey on the milk yield and microbial contamination was developed. Milk samples from 89 dairy farmers in the urban and periurban area of Maroua, divided in 11 groups, matching the Groupe d'Initiative Commune (groups of common interest - GICs), were analyzed for yield, pH value, temperature, density and microbial contamination. The belonging to the different groups of farmers had a statistical influence on milk quantity and density, according to the feed availability. As well the season had an influence on all the quality and quantity parameters. The time and season of delivery affected significantly the milk quality, instead no influence was attributed to the microbial contamination. The results of this survey showed an adequate qualitative level of the local milk production, which may be improved with a higher feeding system and with a better organisation of the delivery

Signals of Supersymmetric Flavour Models in B Physics

If the mechanism of Supersymmetry breaking is not flavour blind, some flavour symmetry is likely to be needed to prevent excessive flavour changing neutral current effects. We discuss two flavour models (based respectively on a U(2) and on a SU(3) horizontal symmetry) providing a good fit to fermion masses and mixings and particularly constraining the supersymmetry soft breaking terms. We show that, while reproducing successfully the Standard Model fit of the unitarity triangle, it is possible to obtain sizable deviations from the Standard Model predictions for three very clean B-physics observables: the time dependent CP asymmetries in $B_d \to J/\psi K^0$ and in $B_s \to J/\psi \phi$ and the $B_s-\bar{B}_s$ mass difference. Our analysis exhibits with two explicit realizations that in supersymmetric theories with a new flavour structure in addition to the Yukawa matrices there exist concrete potentialities for revealing supersymmetry indirectly in theoretically clean $B$-physics observables.Comment: 18 pages, 7 figures, 3 of which in colo

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

Effects of Lepton Flavour Violation on Chargino Production at the Linear Collider

We study the effects of lepton flavour violation (LFV) on the production processes e+e- --> \chi+_i \chi-_j at a linear collider with longitudinal e+ and e- beam polarizations. In the case of LFV the sneutrino mass eigenstates have no definite flavour, therefore, in the t-channel more than one sneutrino mass eigenstate can contribute to the chargino production cross sections. Our framework is the Minimal Supersymmetric Standard Model (MSSM) including LFV terms. We show that in spite of the restrictions on the LFV parameters due to the current limits on rare lepton decays, the cross section \sigma(e+e- --> \chi+_1 \chi-_1) can change by a factor of 2 or more when varying the LFV mixing angles. We point out that even if the present bound on BR(tau- --> e- gamma) improves by a factor of thousand the influence of LFV on the chargino production cross section can be significant. These results could have an important impact on the strategies for determining the underlying model parameters at the linear collider.Comment: 11pp; final version for JHE

Constraints on Natural MNS Parameters from |U_e3|

The MNS matrix structure emerging as a result of recent neutrino measurements strongly suggests two large mixing angles (solar and atmospheric) and one small angle (|U_e3| << 1). Especially when combined with the neutrino mass hierarchy, these values turn out to impose rather stringent constraints on possible flavor models connecting the three active fermion generations. Specifically, we show that an extremely small value of |U_e3| would require fine tuning of Majorana mass matrix parameters, particularly in the context of seesaw models.Comment: 21 pages, ReVTeX, 2 .eps figure files, updated references and acknowledgment

Minimal Flavour Violation with hierarchical squark masses

In a supersymmetric model with hierarchical squark masses we analyze a pattern of flavour symmetry breaking centered on the special role of the top Yukawa coupling and, by extension, of the full Yukawa couplings for the up-type quarks. For sufficiently heavy squarks of the first and second generation this leads to effective Minimal Flavour Violation of the Flavour Changing Neutral Current amplitudes. For this to happen we determine the bounds on the masses of the heavy squarks with QCD corrections taken into account, properly including previously neglected effects. We believe that the view presented in this paper altogether strengthens the case for hierarchical sfermions.Comment: 13 pages, 1 figure. v2: an equation correcte