2,227 research outputs found

    Sparticle Spectrum of Large Volume Compactification

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    We examine the large volume compactification of Type IIB string theory or its F theory limit and the associated supersymmetry breakdown and soft terms. It is crucial to incorporate the loop-induced moduli mixing, originating from radiative corrections to the Kahler potential. We show that in the presence of moduli mixing, soft scalar masses generically receive a D-term contribution of the order of the gravitino mass m_{3/2} when the visible sector cycle is stabilized by the D-term potential of an anomalous U(1) gauge symmetry, while the moduli-mediated gaugino masses and A-parameters tend to be of the order of m_{3/2}/8pi^2. It is noticed also that a too large moduli mixing can destabilize the large volume solution by making it a saddle point.Comment: 29 page

    Serum levels of matrix metalloproteinases-2 and-9 and their tissue inhibitors in inflammatory neuromuscular disorders

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    We monitored serum levels of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) before and during intravenously applied immunoglobulin (IVIG) therapy in 33 patients with chronic immune-mediated neuropathies and myopathies and 15 controls. Baseline MMP-2 and TIMP-2 serum levels were lower and MMP-9 and TIMP-1 serum levels higher in all patients compared to age-matched controls. Eight days after IVIG treatment, MMP-2, TIMP-2, and TIMP-1 serum levels increased, while MMP-9 serum levels decreased, indicating tissue repair. After 60 days, MMP-9 levels increased, MMP-2 approached normal levels, while TIMP-1 and TIMP-2 serum levels were below day 8 levels, indicating relapsing tissue damage. Comparing the MMP/TIMP results with the clinical courses, IVIG treatment tended to change MMP/TIMP levels in a way that paralleled clinical improvement and relapse. In sum, during a distinct time period, IVIG therapy seems to be able to modulate VIMP-mediated tissue repair. Copyright (c) 2006 S. Karger AG, Basel

    TeV scale mirage mediation in NMSSM

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    We study the next-to-minimal supersymmetric standard model. We consider soft supersymmetry breaking parameters, which are induced by the mirage mediation mechanism of supersymmetry breaking. We concentrate on the mirage mediation, where the so-called mirage scale is the TeV scale. In this scenario, we can realize the up-type Higgs soft mass of O(200) GeV, while other masses such as gaugino masses and stop masses are heavy such as 1 TeV or more. Cancellation between the effective \mu-term and the down-type Higgs soft mass ameliorates the fine-tuning in the electroweak symmetry breaking even for \mu=O(500) GeV. The mixing between the doublet and singlet Higgs bosons is suppressed by (\lambda/\kappa)/tan\beta. Then the lightest doublet Higgs mass naturally reaches 125 GeV lifted by the new quartic coupling. The higgsino and singlino are light and their linear combination is the lightest superparticle.Comment: 24 pages, 24 figures, Numerical analysis is replaced with the version calculated by NMSSMTools. Comments and references are added on the suppressed doublet-singlet mixing and cases in which the 125 GeV boson is the 2nd lightest CP-even scalar. The version accepted by JHE

    Methods for genetic manipulation of Burkholderia gladioli pathovar cocovenenans

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    <p>Abstract</p> <p>Background</p> <p><it>Burkholderia gladioli </it>pathovar <it>cocovenenans </it>(BGC) is responsible for sporadic food-poisoning outbreaks with high morbidity and mortality in Asian countries. Little is known about the regulation of virulence factor and toxin production in BGC, and studies in this bacterium have been hampered by lack of genetic tools.</p> <p>Findings</p> <p>Establishment of a comprehensive antibiotic susceptibility profile showed that BGC strain ATCC33664 is susceptible to a number of antibiotics including aminoglycosides, carbapenems, fluoroquinolones, tetracyclines and trimethoprim. In this study, we established that gentamicin, kanamycin and trimethoprim are good selection markers for use in BGC. Using a 10 min method for preparation of electrocompetent cells, the bacterium could be transformed by electroporation at high frequencies with replicative plasmids containing the pRO1600-derived origin of replication. These plasmids exhibited a copy number of > 100 in BGC. When co-conjugated with a transposase expressing helper plasmid, mini-Tn<it>7 </it>vectors inserted site- and orientation-specifically at a single <it>glmS</it>-associated insertion site in the BGC genome. Lastly, a <it>Himar1 </it>transposon was used for random transposon mutagenesis of BGC.</p> <p>Conclusions</p> <p>A series of genetic tools previously developed for other Gram-negative bacteria was adapted for use in BGC. These tools now facilitate genetic studies of this pathogen and allow establishment of toxin biosynthetic pathways and their genetic regulation.</p

    Phenomenological Implications of Deflected Mirage Mediation: Comparison with Mirage Mediation

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    We compare the collider phenomenology of mirage mediation and deflected mirage mediation, which are two recently proposed "mixed" supersymmetry breaking scenarios motivated from string compactifications. The scenarios differ in that deflected mirage mediation includes contributions from gauge mediation in addition to the contributions from gravity mediation and anomaly mediation also present in mirage mediation. The threshold effects from gauge mediation can drastically alter the low energy spectrum from that of pure mirage mediation models, resulting in some cases in a squeezed gaugino spectrum and a gluino that is much lighter than other colored superpartners. We provide several benchmark deflected mirage mediation models and construct model lines as a function of the gauge mediation contributions, and discuss their discovery potential at the LHC.Comment: 29 pages, 9 figure

    Thermal production of axino Dark Matter

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    We reconsider thermal production of axinos in the early universe, adding: a) missed terms in the axino interaction; b) production via gluon decays kinematically allowed by thermal masses; c) a precise modeling of reheating. We find an axino abunance a few times larger than previous computations.Comment: 6 pages, 2 figures. Final version, to appear on JHE

    Kahler Independence of the G2-MSSM

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    The G2-MSSM is a model of particle physics coupled to moduli fields with interesting phenomenology both for colliders and astrophysical experiments. In this paper we consider a more general model - whose moduli Kahler potential is a completely arbitrary G2-holonomy Kahler potential and whose matter Kahler potential is also more general. We prove that the vacuum structure and spectrum of BSM particles is largely unchanged in this much more general class of theories. In particular, gaugino masses are still supressed relative to the gravitino mass and moduli masses. We also consider the effects of higher order corrections to the matter Kahler potential and find a connection between the nature of the LSP and flavor effects.Comment: Final version, matches the version published in JHE

    Singlet-doublet Higgs mixing and its implications on the Higgs mass in the PQ-NMSSM

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    We examine the implications of singlet-doublet Higgs mixing on the properties of a Standard Model (SM)-like Higgs boson within the Peccei-Quinn invariant extension of the NMSSM (PQ-NMSSM). The SM singlet added to the Higgs sector connects the PQ and visible sectors through a PQ-invariant non-renormalizable K\"ahler potential term, making the model free from the tadpole and domain-wall problems. For the case that the lightest Higgs boson is dominated by the singlet scalar, the Higgs mixing increases the mass of a SM-like Higgs boson while reducing its signal rate at collider experiments compared to the SM case. The Higgs mixing is important also in the region of parameter space where the NMSSM contribution to the Higgs mass is small, but its size is limited by the experimental constraints on the singlet-like Higgs boson and on the lightest neutralino constituted mainly by the singlino whose Majorana mass term is forbidden by the PQ symmetry. Nonetheless the Higgs mixing can increase the SM-like Higgs boson mass by a few GeV or more even when the Higgs signal rate is close to the SM prediction, and thus may be crucial for achieving a 125 GeV Higgs mass, as hinted by the recent ATLAS and CMS data. Such an effect can reduce the role of stop mixing.Comment: 26 pages, 3 figures; published in JHE

    Light Higgsino in Heavy Gravitino Scenario with Successful Electroweak Symmetry Breaking

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    We consider, in the context of the minimal supersymmetric standard model, the case where the gravitino weighs 10^6 GeV or more, which is preferred by various cosmological difficulties associated with unstable gravitinos. Despite the large Higgs mixing parameter B together with the little hierarchy to other soft supersymmetry breaking masses, a light higgsino with an electroweak scale mass leads to successful electroweak symmetry breaking, at the price of fine-tuning the higgsino mixing mu parameter. Furthermore the light higgsinos produced at the decays of gravitinos can constitute the dark matter of the universe. The heavy squark mass spectrum of O(10^4) GeV can increase the Higgs boson mass to about 125 GeV or higher.Comment: 13 pages, 3 figures; v2: version to appear in JHE

    Spinor-Vector Duality in Heterotic String Orbifolds

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    The three generation heterotic-string models in the free fermionic formulation are among the most realistic string vacua constructed to date, which motivated their detailed investigation. The classification of free fermion heterotic string vacua has revealed a duality under the exchange of spinor and vector representations of the SO(10) GUT symmetry over the space of models. We demonstrate the existence of the spinor-vector duality using orbifold techniques, and elaborate on the relation of these vacua to free fermionic models.Comment: 20 pages. v2 minor corrections. Version to appear on JHEP. v3 misprints correcte
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