8,320 research outputs found

    New Technologies, Workplace Organisation and the Age Structure of the Workforce: Firm-Level Evidence

    Get PDF
    This paper investigates the relationships between new technologies, innovative workplace practices and the age structure of the workforce in a sample of French manufacturing firms. We find evidence that the wage bill share of older workers is lower in innovative firms and that the opposite holds for younger workers. This age bias is also evidenced within occupational groups, thus suggesting that skills do not completely protect workers against the labour market consequences of ageing. More detailed analysis of employment inflows and outflows shows that new technologies essentially affect older workers through reduced hiring opportunities, whereas organisational innovations mainly increase their probability of exit. This suggests that some skill obsolescence may be at work in our sample.new work practices, technology, older workers, labour demand

    QCD Approach to B->D \pi Decays and CP Violation

    Full text link
    The branching ratios and CP violations of the B→DπB\to D\pi decays, including both the color-allowed and the color-suppressed modes, are investigated in detail within QCD framework by considering all diagrams which lead to three effective currents of two quarks. An intrinsic mass scale as a dynamical gluon mass is introduced to treat the infrared divergence caused by the soft collinear approximation in the endpoint regions, and the Cutkosky rule is adopted to deal with a physical-region singularity of the on mass-shell quark propagators. When the dynamical gluon mass ÎŒg\mu_g is regarded as a universal scale, it is extracted to be around ÎŒg=440\mu_g = 440 MeV from one of the well-measured B→DπB\to D\pi decay modes. The resulting predictions for all branching ratios are in agreement with the current experimental measurements. As these decays have no penguin contributions, there are no direct CPCP asymmetries. Due to interference between the Cabibbo-suppressed and the Cabibbo-favored amplitudes, mixing-induced CP violations are predicted in the B→D±π∓B\to D^{\pm}\pi^{\mp} decays to be consistent with the experimental data at 1-σ\sigma level. More precise measurements will be helpful to extract weak angle 2ÎČ+Îł2\beta+\gamma.Comment: 21pages,5 figures,3 tables, typos corrected and numerical result for one of decay channels is improve

    An Improved Standard Model Prediction Of BR(B -> tau nu) And Its Implications For New Physics

    Full text link
    The recently measured B -> tau nu branching ratio allows to test the Standard Model by probing virtual effects of new heavy particles, such as a charged Higgs boson. The accuracy of the test is currently limited by the experimental error on BR(B -> tau nu) and by the uncertainty on the parameters fB and |Vub|. The redundancy of the Unitarity Triangle fit allows to reduce the error on these parameters and thus to perform a more precise test of the Standard Model. Using the current experimental inputs, we obtain BR(B -> tau nu)_SM = (0.84 +- 0.11)x10^{-4}, to be compared with BR(B -> tau nu)_exp = (1.73 +- 0.34)x10^{-4}. The Standard Model prediction can be modified by New Physics effects in the decay amplitude as well as in the Unitarity Triangle fit. We discuss how to disentangle the two possible contributions in the case of minimal flavour violation at large tan beta and generic loop-mediated New Physics. We also consider two specific models with minimal flavour violation: the Type-II Two Higgs Doublet Model and the Minimal Supersymmetric Standard Model.Comment: 7 pages, 13 figures, 1 table. v2: added references and discussion of B -> D tau nu in the 2HDM. v3: added Bs->mumu in the 2HDM. Final version to appear in PL

    Light hadron, Charmonium(-like) and Bottomonium(-like) states

    Full text link
    Hadron physics represents the study of strongly interacting matter in all its manifestations and the understanding of its properties and interactions. The interest on this field has been revitalized by the discovery of new light hadrons, charmonium- and bottomonium-like states. I review the most recent experimental results from different experiments.Comment: Presented at Lepton-Photon 2011, Mumbai, India; 21 pages, 18 figures; add more references; some correctio

    Comparison between backscattered TerraSAR signals and simulations from the radar backscattering models IEM, Oh, and Dubois

    Get PDF
    The objective of this paper is to evaluate on bare soils the surface backscattering models IEM, Oh, and Dubois in X-band. This analysis uses a large database of TerraSAR-X images and in situ measurements (soil moisture and surface roughness). Oh's model correctly simulates the radar signal for HH and VV polarizations whereas the simulations performed with the Dubois model show a poor correlation between TerraSAR data and model. The backscattering Integral Equation Model (IEM) model simulates correctly the backscattering coefficient only for rms1.5 cm in using Gaussian function. However, the results are not satisfactory for a use of IEM in the inversion of TerraSAR data. A semi-empirical calibration of IEM was done in X-band. Good agreement was found between the TerraSAR data and the simulations using the calibrated version of the IEM

    An improved observable for the forward-backward asymmetry in B -> K* l+ l- and Bs -> phi l+ l-

    Full text link
    We study the decay B -> K* l+ l- in the QCD factorization approach and propose a new integrated observable whose dependence on the form factors is almost negligible, consequently the non--perturbative error is significantly reduced and indeed its overall theoretical error is dominated by perturbative scale uncertainties. The new observable we propose is the ratio between the integrated forward--backward asymmetry in the [4,6] GeV^2 and [1,4] GeV^2 dilepton invariant mass bins. This new observable is particularly interesting because, when compared to the location of the zero of the FBA spectrum, it is experimentally easier to measure and its theoretical uncertainties are almost as small; moreover it displays a very strong dependence on the phase of the Wilson coefficient C_10 that is otherwise only accessible through complicated CP violating asymmetries. We illustrate the new physics sensitivity of this observable within the context of few extensions of the Standard Model, namely the SM with four generations, an MSSM with non--vanishing source of flavor changing neutral currents in the down squark sector and a Z' model with tree level flavor changing couplings.Comment: 19 pages, 7 figure

    How the recent BABAR data for P to \gamma\gamma* affect the Standard Model predictions for the rare decays P to l+l-

    Full text link
    Measuring the lepton anomalous magnetic moments (g−2)(g-2) and the rare decays of light pseudoscalar mesons into lepton pairs P→l+l−P\to l^{+}l^{-} , serve as important tests of the Standard Model. To reduce the theoretical uncertainty in the standard model predictions, the data on the charge and transition form factors of the light pseudoscalar mesons play a significant role. Recently, new data on the behavior of the transition form factors P→γγ∗P\to\gamma\gamma* at large momentum transfer were supplied by the BABAR collaboration. There are several problems with the theoretical interpretation of these data: 1) An unexpectedly slow decrease of the pion transition form factor at high momenta, 2) the qualitative difference in the behavior of the pion form factor and the η\eta and ηâ€Č\eta^\prime form factors at high momenta, 3) the inconsistency of the measured ratio of the η\eta and ηâ€Č\eta^\prime form factors with the predicted one. We comment on the influence of the new BABAR data on the rare decay branchings.Comment: 11 pages, 3 figure
    • 

    corecore