29 research outputs found

    Radiative Generation of the LMA Solution from Small Solar Neutrino Mixing at the GUT Scale

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    We show that in see-saw models with small or even vanishing lepton mixing angle θ12\theta_{12}, maximal θ23\theta_{23}, zero θ13\theta_{13} and zero CP phases at the GUT scale, the currently favored LMA solution of the solar neutrino problem can be obtained in a rather natural way by Renormalization Group effects. We find that most of the running takes place in the energy ranges above and between the see-saw scales, unless the charged lepton Yukawa couplings are large, which would correspond to a large tanβ\tan \beta in the Minimal Supersymmetric Standard Model (MSSM). The Renormalization Group evolution of the solar mixing angle θ12\theta_{12} is generically larger than the evolution of θ13\theta_{13} and θ23\theta_{23}. A large enhancement occurs for an inverted mass hierarchy and for a regular mass hierarchy with m2m1m2+m1|m_2 - m_1| \ll |m_2 + m_1|. We present numerical examples of the evolution of the lepton mixing angles in the Standard Model and the MSSM, in which the current best-fit values of the LMA mixing angles are produced with vanishing solar mixing angle θ12\theta_{12} at the GUT scale.Comment: 10 pages, 6 figures; reference added, minor changes in the text; results unchanged; final version to appear in JHE

    Predictions for Proton Lifetime in Minimal Non-Supersymmetric SO(10) Models: An Update

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    We present our best estimates of the uncertainties due to heavy particle threshold corrections on the unification scale MUM_U, intermediate scale MIM_I and coupling constant Alpha_U in the minimal non-supersymmetric SO(10) models. Using these , we update the predictions for proton life-time in these models.Comment: UMD-PP-94-117 ( 20 pages;latex; no figures

    Project management between will and representation

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    This article challenges some deep-rooted assumptions of project management. Inspired by the work of the German philosopher, Arthur Schopenhauer, it calls for looking at projects through two complementary lenses: one that accounts for cognitive and representational aspects and one that accounts for material and volitional aspects. Understanding the many ways in which these aspects transpire and interact in projects sheds new light on project organizations, as imperfect and fragile representations that chase a shifting nexus of intractable human, social, technical, and material processes. This, in turn, can bring about a new grasp of notions such as value,\ud knowledge, complexity, and risk

    Prospects for e+e- physics at Frascati between the phi and the psi

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    We present a detailed study, done in the framework of the INFN 2006 Roadmap, of the prospects for e+e- physics at the Frascati National Laboratories. The physics case for an e+e- collider running at high luminosity at the phi resonance energy and also reaching a maximum center of mass energy of 2.5 GeV is discussed, together with the specific aspects of a very high luminosity tau-charm factory. Subjects connected to Kaon decay physics are not discussed here, being part of another INFN Roadmap working group. The significance of the project and the impact on INFN are also discussed. All the documentation related to the activities of the working group can be found in http://www.roma1.infn.it/people/bini/roadmap.html.Comment: INFN Roadmap Report: 86 pages, 25 figures, 9 table
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