12,314 research outputs found

    Unparticle Physics in Single Top Signals

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    We study the single production of top quarks in e+e,epe^+e^-, ep and pppp collisions in the context of unparticle physics through the Flavor Violating (FV) unparticle vertices and compute the total cross sections for single top production as functions of scale dimension d_{\U}. We find that among all, LHC is the most promising facility to probe the unparticle physics via single top quark production processes.Comment: 14 pages, 10 figure

    Dynamical Generation of Linear σ\sigma model SU(3) Lagrangian and Meson Nonet Mixing

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    This paper is the SU(3) extension of the dynamically generated SU(2) linear σ\sigma model Lagrangian worked out previously using dimensional regularization. After discussing the quark-level Goldberger-Treiman relations for SU(3) and the related gap equations, we dynamically generate the meson cubic and quartic couplings. This also constrains the meson-quark coupling constant to g=2π/3g=2\pi/\sqrt3 and determines the SU(3) scalar meson masses in a Nambu-Jona-Lasinio fashion. Finally we dynamically induce the U(3) pseudoscalar and scalar mixing angles in a manner compatible with data.Comment: 19 printed pages, requires plain Tex, now published in IJMPA 13, 657 (1998

    The structure of the exact effective action and the quark confinement in MSSM QCD

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    An expression for the exact (nonperturbative) effective action of NN=1 supersymmetric gauge theories is proposed, supposing, that all particles except for the gauge bosons are massive. Analysis of its form shows, that instanton effects in the supersymmetric theories can lead to the quark confinement. The typical scale of confinement in MSSM QCD, calculated from the first principles, is in agreement with the experimental data. The proposed explanation is quite different from the dual Higgs mechanism.Comment: Final version to appear in Sov.J.Nucl.Phys. Some insignificant errors and misprints are correcte

    Non-minimal Split Supersymmetry

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    We present an extension of the minimal split supersymmetry model, which is capable of explaining the baryon asymmetry of the Universe. Instead of MSSM we start from NMSSM and split its spectrum in such a way that the low energy theory contains neutral particles, in addition to the content of minimal split supersymmetry. They trigger the strongly first order electroweak phase transition (EWPT) and provide an additional source of CP-violation. In this model, we estimate the amount of the baryon asymmetry produced during EWPT, using WKB approximation for CP-violating sources in diffusion equations. We also examine the contribution of CP-violating interactions to the electron and neutron electric dipole moments and estimate the production of the neutralino dark matter. We find that both phenomenological and cosmological requirements can be fulfilled in this model.Comment: 31 pages, 9 figures, typos correcte

    Loop bounds on non-standard neutrino interactions

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    We reconsider the bounds on non-standard neutrino interactions with matter which can be derived by constraining the four-charged-lepton operators induced at the loop level. We find that these bounds are model dependent. Naturalness arguments can lead to much stronger constraints than those presented in previous studies, while no completely model-independent bounds can be derived. We will illustrate how large loop-contributions to four-charged-lepton operators are induced within a particular model that realizes gauge invariant non-standard interactions and discuss conditions to avoid these bounds. These considerations mainly affect the O(104)\mathcal O(10^{-4}) constraint on the non-standard coupling strength \eps_{e\mu}, which is lost. The only model-independent constraints that can be derived are O(101)\mathcal O(10^{-1}). However, significant cancellations are required in order to saturate this bound.Comment: Minor changes, version to be published in JHEP. 17 pages, 3 Axodraw figures, REVTeX

    Charged Lepton Electric Dipole Moments from TeV Scale Right-handed Neutrinos

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    We study the connection between charged lepton electric dipole moments, dld_l (l=e,μ,τ)(l=e,\mu,\tau), and seesaw neutrino mass generation in a simple two Higgs doublet extension of the Standard Model plus three right-handed neutrinos (RHN) NaN_a, a=1,2,3a=1,2,3. For RHN with hierarchical masses and at least one with mass in the 10 TeV range we obtain the upper bounds of de<9×1030|d_e|< 9\times 10^{-30} e-cm and dμ<2×1026|d_{\mu}|<2 \times 10^{-26} e-cm. Our scenario favors the normal mass hierarchy for the light neutrinos. We also calculated the cross section for e^-e^- \ra W^- W^- in a high luminosity collider with constraints from neutrinoless double beta decay of nuclei included. Among the rare muon decay experiments we find that \mu\ra e\gamma is most sensitive and the upper limit is <8×1013<8\times 10^{-13}.Comment: references added, typos correcte

    Spontaneous CP Violation in Non-Minimal Supersymmetric Models

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    We study the possibilities of spontaneous CP violation in the Next-to-Minimal Supersymmetric Standard Model with an extra singlet tadpole term in the scalar potential. We calculate the Higgs boson masses and couplings with radiative corrections including dominant two loop terms. We show that it is possible to satisfy the LEP constraints on the Higgs boson spectrum with non-trivial spontaneous CP violating phases. We also show that these phases could account for the observed value of epsilonK.Comment: 21 pages, 7 Figures in Encapsulated Postscrip
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