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Publications (6)0 Total impact

  • Article: Displaced multileptons at the LHC -- probing a 125 GeV new boson in $\mu\nu$SSM
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    ABSTRACT: The $\mu\nu$SSM provides a solution to the $\mu$-problem of the minimal supersymmetric standard model and accounts for light neutrino masses by simply using right-handed neutrino superfields. As a consequence of this mechanism, R-parity is broken. We discuss possible signals of the $\mu\nu$SSM at the LHC, in view of the recent discovery by ATLAS and CMS experiments of a new particle compatible with the standard model Higgs boson. We show that the $\mu\nu$SSM will manifest itself in events with multileptons originating from displaced vertices.
    11/2012;
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    Article: The Higgs sector of the munuSSM and collider physics
    Javier Fidalgo, Daniel E. Lopez-Fogliani, Carlos Munoz, Roberto Ruiz de Austri
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    ABSTRACT: The $\mu\nu$SSM is a supersymmetric standard model that accounts for light neutrino masses and solves the $\mu$ problem of the MSSM by simply using right-handed neutrino superfields. Since this mechanism breaks R-parity, a peculiar structure for the mass matrices is generated. The neutral Higgses are mixed with the right- and left-handed sneutrinos producing 8$\times$8 neutral scalar mass matrices. We analyse the Higgs sector of the $\mu\nu$SSM in detail, with special emphasis in possible signals at colliders. After studying in general the decays of the Higges, we focus on those processes that are genuine of the $\mu\nu$SSM, and could serve to distinguish it from other supersymmetric models. In particular, we present viable benchmark points for LHC searches. For example, we find decays of a MSSM-like Higgs into two lightest neutralinos, with the latter decaying inside the detector leading to displaced vertices, and producing final states with 4 and 8 $b$-jets plus missing energy. Final states with leptons and missing energy are also found.
    07/2011;
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    Article: The seesaw mechanism in the $\mu \nu$SSM
    Daniel E. Lopez-Fogliani
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    ABSTRACT: The $\mu \nu$SSM proposes to use right-handed neutrino supermultiplets in order to generate the $\mu$ term and neutrino masses simultaneously. We discuss neutrino physics and the associated electroweak seesaw mechanism in this model. We show how to obtain, from the neutralino-neutrino mass matrix of the $\mu \nu$SSM, the effective neutrino mass matrix. In particular we discuss certain limits of this matrix that clarify the neutrino-sector behavior of the model. We also show that current data on neutrino masses and mixing angles can easily be reproduced. These constraints can be fulfilled even with a diagonal neutrino Yukawa matrix, since this seesaw does not involve only the right-handed neutrinos but also the MSSM neutralinos. To obtain the correct neutrino angles turns out to be easy due to the following characteristics of this seesaw: R-parity is broken and the relevant scale is the electroweak one. Comment: 7 pages, 1 figure. Talk given at "BUE, CTP International Conference on Neutrino Physics in the LHC Era", Luxor, Egypt, 15-19 Nov. 2009.
    04/2010;
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    Article: A Bayesian Analysis of the Constrained NMSSM
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    ABSTRACT: We perform a first global exploration of the Constrained Next-to-Minimal Supersymmetric Standard Model using Bayesian statistics. We derive several global features of the model and find that, in some contrast to initial expectations, they closely resemble the Constrained MSSM. This remains true even away from the decoupling limit which is nevertheless strongly preferred. We present ensuing implications for several key observables, including collider signatures and predictions for direct detection of dark matter.
    06/2009;
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    Article: Gamma-ray detection from gravitino dark matter decay in the $\mu\nu$SSM
    Ki-Young Choi, Daniel E. Lopez-Fogliani, Carlos Munoz, Roberto Ruiz de Austri
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    ABSTRACT: The $\mu\nu$SSM provides a solution to the $\mu$-problem of the MSSM and explains the origin of neutrino masses by simply using right-handed neutrino superfields. Given that R-parity is broken in this model, the gravitino is a natural candidate for dark matter since its lifetime becomes much longer than the age of the Universe. We consider the implications of gravitino dark matter in the $\mu\nu$SSM, analyzing in particular the prospects for detecting gamma rays from decaying gravitinos. If the gravitino explains the whole dark matter component, a gravitino mass larger than 20 GeV is disfavored by the isotropic diffuse photon background measurements. On the other hand, a gravitino with a mass range between 0.1-20 GeV gives rise to a signal that might be observed by the FERMI satellite. In this way important regions of the parameter space of the $\mu\nu$SSM can be checked. Comment: Final version to appear in JCAP, 13 pages, 3 figures
    06/2009;
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    Article: Analysis of the parameter space and spectrum of the $\mu \nu$SSM
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    ABSTRACT: The $\mu\nu$SSM is a supersymmetric standard model that solves the $\mu$ problem of the MSSM using the R-parity breaking couplings between the right-handed neutrino superfields and the Higgses in the superpotential, $\lambda_{i} \hat \nu^c_i \hat H_d \hat H_u$. The $\mu$ term is generated spontaneously through sneutrino vacuum expectation values, $\mu=\lambda_i < \tilde \nu^c_i>$, once the electroweak symmetry is broken. In addition, the couplings $\kappa_{ijk} \hat \nu^c_i\hat \nu^c_j\hat \nu^c_k$ forbid a global U(1) symmetry avoiding the existence of a Goldstone boson, and also contribute to spontaneously generate Majorana masses for neutrinos at the electroweak scale. Following this proposal, we have analysed in detail the parameter space of the $\mu\nu$SSM. In particular, we have studied viable regions avoiding false minima and tachyons, as well as fulfilling the Landau pole constraint. We have also computed the associated spectrum, paying special attention to the mass of the lightest Higgs. The presence of right and left-handed sneutrino vacuum expectation values leads to a peculiar structure for the mass matrices. The most important consequence is that neutralinos are mixed with neutrinos, and neutral Higgses with sneutrinos.
    11/2008;