71,267 research outputs found

    Closing the Universe by relaxing the cosmological constant

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    We propose a string-inspired model which correlates several aspects of particle physics and cosmology. Inspired by the flat directions and the absence of adjoint Higgs representations found in typical string models, we consider a no-scale SU(5)×U(1)SU(5)\times U(1) supergravity model. This model entails well determined low-energy phenomenology, such as the value of the neutralino dark matter relic abundance and a negative contribution to the vacuum energy. A positive contribution to the vacuum energy is also typically present in string theory as a consequence of the running of the fundamental constants towards their fixed point values. If these two contributions cancel appropriately, one may end up with a vacuum energy which brings many cosmological observations into better agreement with theoretical expectations. The present abundance of neutralinos would then be fixed. We delineate the regions of parameter space allowed in this scenario, and study the ensuing predictions for the sparticle and Higgs-boson masses in this model.Comment: 5 pages, 2 figures (included), Latex, CTP-TAMU-06/9

    A supergravity explanation of the CDF eeγγee\gamma\gamma event

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    We present a unified no-scale supergravity model with a light gravitino that can naturally explain the observed eeγγee\gamma\gamma event at CDF via right-handed selectron pair-production. The full spectrum of our model can be described in terms of a single parameter and can be distinguished from alternative proposals in the literature. Ongoing and future runs at LEP 2 should be able to probe the full allowed parameter space via acoplanar diphoton events from e+e−→χ10χ10e^+e^-\to\chi^0_1\chi^0_1 production.Comment: 10 pages, LaTeX, 4 figures (included

    Identification of large masses of citrus fruit and rice fields in eastern Spain

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    There are no author-identified significant results in this report

    M-theory Inspired No-scale Supergravity

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    We propose a supergravity model that contains elements recently shown to arise in the strongly-coupled limit of the E8×E8E_8\times E_8 heterotic string (M-theory), including a no-scale--like K\"ahler potential, the identification of the string scale with the gauge coupling unification scale, and the onset of supersymmetry breaking at an intermediate scale determined by the size of the eleventh dimension of M-theory. We also study the phenomenological consequences of such scenario, which include a rather constrained sparticle spectrum within the reach of present-generation particle accelerators.Comment: 8 pages, LaTeX, 3 figures (included
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