1,497 research outputs found

    Experimental constraints on the parameter space of the next-to-minimal supersymmetric standard model at LEP 2

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    We search for the neutral Higgs sector of the next-to-minimal supersymmetric standard model at LEP 2. At the tree level any experimental constraints on tanβ\tan \beta cannot be set by the Higgs search at LEP 2 with s\sqrt{s} = 175 GeV, whereas at LEP 2 with s\sqrt{s} = 192 GeV tanβ\tan \beta can be set by an experimental constraint. Furthermore the tree level parameter space of the model can be completely explored by the Higgs search at LEP 2 with s\sqrt{s} = 205 GeV. Radiative corrections both to the neutral Higgs boson masses and to the relevant couplings for the scalar Higgs productions give large contributions to the production cross sections of the scalar Higgs bosons at the tree level. The tree level situation at LEP 2 with s\sqrt{s} = 192 GeV as well as with s\sqrt{s} = 205 GeV can be drastically changed by these effects. We expect that a small region of the 1-loop level parameter space of the model via the scalar Higgs production can be explored by the Higgs search at LEP 2.Comment: 14 pages (3 figures are included

    Duality of Quasilocal Gravitational Energy and Charges with Non-orthogonal Boundaries

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    We study the duality of quasilocal energy and charges with non-orthogonal boundaries in the (2+1)-dimensional low-energy string theory. Quasilocal quantities shown in the previous work and some new variables arisen from considering the non-orthogonal boundaries as well are presented, and the boost relations between those quantities are discussed. Moreover, we show that the dual properties of quasilocal variables such as quasilocal energy density, momentum densities, surface stress densities, dilaton pressure densities, and Neuve-Schwarz(NS) charge density, are still valid in the moving observer's frame.Comment: 19pages, 1figure, RevTe

    Petrogenesis and Geological Significances of Ultramafic Rocks in Hongseong Area, Gyeonggi Massif, South Korea

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    Department of Earth and Environmental SciencesChonbuk National University, Korea金沢大学大学院自然科学研究科Promoting Environmental Pesearch in Pan-Japan Sea Area : Young Researchers\u27 Network, Schedule: March 8-10,2006,Kanazawa Excel Hotel Tokyu, Japan, Organized by: Kanazawa University 21st-Century COE Program, Environmental Monitoring and Prediction of Long- & Short- Term Dynamics of Pan-Japan Sea Area ; IICRC(Ishikawa International Cooperation Research Centre), Sponsors : Japan Sea Research ; UNU-IAS(United Nations University Institute of Advanced Studies)+Ishikawa Prefecture Government ; City of Kanazaw

    Hawking Temperature in Taub-NUT (A)dS spaces via the Generalized Uncertainty Principle

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    Using the extended forms of the Heisenberg uncertainty principle from string theory and the quantum gravity theory, we drived Hawking temperature of a Taub-Nut-(A)dS black hole. In spite of their distinctive natures such as asymptotically locally flat and breakdown of the area theorem of the horizon for the black holes, we show that the corrections to Hawking temperature by the generalized versions of the the Heisenberg uncertainty principle increases like the Schwarzschild-(A)dS black hole and give the reason why the Taub-Nut-(A)dS metric may have AdS/CFT dual picture.Comment: version published in General Relativity and Gravitatio

    Neutral Higgs bosons in the MNMSSM with explicit CP violation

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    Within the framework of the minimal non-minimal supersymmetric standard model (MNMSSM) with tadpole terms, CP violation effects in the Higgs sector are investigated at the one-loop level, where the radiative corrections from the loops of the quark and squarks of the third generation are taken into account. Assuming that the squark masses are not degenerate, the radiative corrections due to the stop and sbottom quarks give rise to CP phases, which trigger the CP violation explicitly in the Higgs sector of the MNMSSM. The masses, the branching ratios for dominant decay channels, and the total decay widths of the five neutral Higgs bosons in the MNMSSM are calculated in the presence of the explicit CP violation. The dependence of these quantities on the CP phases is quite recognizable, for given parameter values.Comment: 25 pages, 8 figure

    Neutral Higgs sector of the next-to-minimal supersymmetric standard model with explicit CP violation

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    The neutral Higgs sector of the next-to-minimal supersymmetric standard model (NMSSM) with explicit CP violation is investigated at the 1-loop level, using the effective potential method; not only the loops involving the third generation of quarks and scalar quarks, but also the loops involving WW boson, charged Higgs boson, and chargino are taken into account. It is found that for some parameter values of the NMSSM the contributions from the WW boson, charged Higgs boson, and chargino loops may modify the masses of the neutral Higgs bosons and the mixings among them significantly, depending on the CP phase. In e+ee^+e^- collisions, the prospects for discovering neutral Higgs bosons are investigated within the context of the NMSSM with explicit CP violation when the dominant component of the lightest neutral Higgs boson is the Higgs singlet field of the NMSSM.Comment: Latex, 23 pages, 6 figure

    Possibility of spontaneous CP violation in the nonminimal supersymmetric standard model with two neutral Higgs singlets

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    A supersymmetric standard model with two Higgs doublets and two Higgs singlets is investigated if it can accommodate the possibility of spontaneous CP violation. Assuming the degeneracy of the scalar quark masses of the third generation, we find that spontaneous CP violation in the Higgs sector is viable in our model. In the case of spontaneous CP violation, the masses of the lightest two neutral Higgs bosons are estimated to be 80 and 125 GeV for some parameter values in our model, which, are consistent with LEP2 data.Comment: 18 pages, 3figure

    Zirconolite and baddeleyite in an ultramafic suite from southern India: Early Ordovician carbonatite-type melts associated with extensional collapse of the Gondwana crust

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    金沢大学理工研究域自然システム学系We report here the occurrence of rare zirconium-bearing minerals, zirconolite (CaZrTi2O7) and baddeleyite (ZrO2), from an unusual ultramafic suite within the Achankovil Shear Zone (ACSZ) in southern India. Zirconolite occurs as inclusions within spinel in phlogopite-graphite spinellite and shows characteristic development of radial cracks. Baddeleyite is commonly observed as an included phase within phlogopite from phlogopite dunite and graphite-spinel glimmerite. The mineral also occurs less commonly within spinel and graphite from graphite-spinel glimmerite. The composition of zirconolite is characterized by an enrichment of U and Th over rare earth elements. Baddeleyite shows abundance of Zr with minor Hf, Ti, and U. The mode of occurrence along with the chemical composition of these minerals implies their formation as early-stage crystallization products from a silica-undersaturated melt that was enriched in "carbonatite-phile elements" such as Ca, Zr, Ti, and volatiles CO2 and H2O. We report U-Pb chemical ages from the zirconolite that show a mean of 469 ± 11 Ma. We correlate this age with the timing of emplacement and consolidation of the ultramafic suite within ACSZ, and it is considerably younger than the late Neoproterozoic-Cambrian ages reported from this zone. Our data suggest early Ordovician carbonatite-type melts emplaced within ACSZ, which we identify as a mantle-rooted zone. We infer that deep-seated extension along the ACSZ probably triggered the generation of such melts, related to the extensional collapse of the orogen following the collisional assembly of the Gondwana supercontinent. © 2006 by The University of Chicago. All rights reserved

    Charged Higgs boson in the next-to-minimal supersymmetric standard model with explicit CP violation

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    The phenomenology of the explicit CP violation in the Higgs sector of the next-to-minimal supersymmetric standard model (NMSSM) is investigated, with emphasis on the charged Higgs boson. The radiative corrections due to both quarks and scalar-quarks of the third generation are taken into account, and the negative result of the search for the Higgs bosons at CERN LEP2, with the discovery limit of 0.1 pb, is imposed as a constraint. It is found that there are parameter regions of the NMSSM where the lightest neutral Higgs boson may even be massless, without being detected at LEP2. This implies that the LEP2 data do not contradict the existence of a massless neutral Higgs boson in the NMSSM. For the charged Higgs boson, the radiative corrections to its mass may be negative in some parameter regions of the NMSSM. The phenomenological lower bound on the radiatively corrected mass of the charged Higgs boson is increased as the CP violation becomes maximal, i.e., as the CP violating phase becomes π/2\pi/2. At the maximal CP violation, its lower bound is about 110 GeV for 5 tanβ\leqslant \tan \beta \leqslant 40. The vacuum expectation value (VEV) of the neutral Higgs singlet is shown to be no smaller than 16 GeV for any parameter values of the NMSSM with explicit CP violation. This value of the lower limit is found to increase up to about 45 GeV as the ratio (tanβ\tan \beta) of the VEVs of the two Higgs doublets decreases to smaller values (\sim 2). The discovery limit of the Higgs boson search at LEP2 is found to cover about a half of the kinematically allowed part of the whole parameter space of the NMSSM, and the portion is roughly stable against the CP violating phase.Comment: Latex, 24 pages, 6 figure

    Explicit CP violation in the Dine-Seiberg-Thomas model

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    The possibility of explicit CP violation is studied in a supersymmetric model proposed by Dine, Seiberg, and Thomas, with two effective dimension-five operators. The explicit CP violation may be triggered by complex phases in the coefficients for the dimension-five operators in the Higgs potential, and by a complex phase in the scalar top quark masses. Although the scenario of explicit CP violation is found to be inconsistent with the experimental data at LEP2 at the tree level, it may be possible at the one-loop level. For a reasonable parameter space, the masses of the neutral Higgs bosons and their couplings to a pair of ZZ bosons are consistent with the LEP2 data, at the one-loop level.Comment: 5 pages, 2 figure
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