4,349 research outputs found

    Neutron electric dipole moment from gauge/string duality

    Get PDF
    We compute the electric dipole moment of nucleons in the large NcN_c QCD model by Witten, Sakai and Sugimoto with Nf=2N_f=2 degenerate massive flavors. Baryons in the model are instantonic solitons of an effective five-dimensional action describing the whole tower of mesonic fields. We find that the dipole electromagnetic form factor of the nucleons, induced by a finite topological θ\theta angle, exhibits complete vector meson dominance. We are able to evaluate the contribution of each vector meson to the final result - a small number of modes are relevant to obtain an accurate estimate. Extrapolating the model parameters to real QCD data, the neutron electric dipole moment is evaluated to be dn=1.8⋅10−16 θ  e⋅cmd_n = 1.8 \cdot 10^{-16}\, \theta\;e\cdot \mathrm{cm}. The electric dipole moment of the proton is exactly the opposite.Comment: Latex, 4 pages; v2: minor corrections, few comments adde

    Assessing the effect of the CAP on farm innovation adoption. An analysis in two French regions

    Get PDF
    Literature on innovation adoption mechanism has emphasised the positive effect of Single Farm Payments (SFP) and Rural Development Payments on adoption of new technologies. In this context, the expected process of CAP reforming after 2013 is likely to strengthen the role of innovation in the European Union (EU). The objective of this paper is to identify the determinants of the adoption of future innovation, in particular in connection to past innovation, and to assess the role of agricultural policy in the promotion of innovation adoption. The analysis is applied to two regions (Centre and Midi-Pyrénées) in France. Two separate Count models are developed in order to explain famers’ stated intention concerning different intensities of innovation adoption under two different policy scenarios. Preliminary results highlight that the CAP strongly affects the decision to innovate and the innovation intensity, even if there is no statistical significance for the variable connected to the amount of payments or the level of payment per hectare
    • …
    corecore