Carlos Muñoz

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We study in a systematic and modular invariant way gaugino condensation in the hidden sector as a potential source of hierarchical supersymmetry breaking and a non–trivial potential for the dilaton S whose real part corresponds to the tree level gauge coupling constant (Re S ∼ g gut). For the case of pure Yang–Mills condensation, we show that no realistic(More)
The fact that neutrinos are massive suggests that the Minimal Supersymmetric Standard Model (MSSM) might be extended in order to include three gauge-singlet neutrino superfields with Yukawa couplings of the type H2 Lν . We propose to use these superfields to solve the μ problem of the MSSM without having to introduce an extra singlet superfield as in the(More)
A complete analysis of all the potentially dangerous directions in the field-space of the minimal supersymmetric standard model is carried out. They are of two types, the ones associated with the existence of charge and color breaking minima in the potential deeper than the realistic minimum and the directions in the field-space along which the potential(More)
Assuming that the Standard Model of particle physics arises from the E8×E8 Heterotic String Theory, we try to solve the discrepancy between the unification scale predicted by this theory (≈ gGUT × 5.27 · 1017 GeV) and the value deduced from LEP experiments (≈ 2 · 1016 GeV). A crucial ingredient in our solution is the presence at low energies of three(More)
We show that the observed structure of quark and lepton masses and mixing angles can arise entirely geometrically from superstring constructions, at the renormalizable level. The model we consider is a Z3 orbifold compactification of heterotic string with two Wilson lines, where three families of particles of SU(3)c × SU(2)L × U(1)Y , including Higgses, are(More)
We provide a simple macroscopic analysis of the four-dimensional effective supergravity of the Hořava-Witten M -theory which is expanded in powers of κ2/3/ρV 1/3 and κ2/3ρ/V 2/3 where κ2, V and ρ denote the eleven-dimensional gravitational coupling, the Calabi-Yau volume and the eleventh length respectively. Possible higher order terms in the Kähler(More)
We analyse the direct detection of neutralino dark matter in supergravity scenarios with non-universal soft scalar and gaugino masses. In particular, the neutralino-nucleon cross section is computed and compared with the sensitivity of detectors. We take into account the most recent experimental and astrophysical constraints on the parameter space,(More)
Supersymmetry breaking in string perturbation theory predicts the existence of a new dimension at the TeV scale. The simplest realization of the minimal supersymmetric Standard Model in the context of this mechanism has two important consequences: (i) A natural solution to the μ-problem; (ii) The absence of quadratic divergences in the cosmological(More)
We study the phenomenology of the strong–coupling limit of E8 × E8 heterotic string obtained from M–theory, using a Calabi–Yau compactification. After summarizing the standard embedding results, we concentrate on non– standard embedding vacua as well as vacua where non–perturbative objects as five–branes are present. We analyze in detail the different(More)