26 research outputs found

    SS Parameter in the Holographic Walking/Conformal Technicolor

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    We explicitly calculate the SS parameter in entire parameter space of the holographic walking/conformal technicolor (W/C TC), based on the deformation of the holographic QCD by varying the anomalous dimension from γm0\gamma_m \simeq 0 through γm1\gamma_m \simeq 1 continuously. The SS parameter is given as a positive monotonic function of ξ\xi which is fairly insensitive to γm\gamma_m and continuously vanishes as Sξ20S \sim \xi^2 \to 0 when ξ0\xi \to 0, where ξ\xi is the vacuum expectation value of the bulk scalar field at the infrared boundary of the 5th dimension z=zmz=z_m and is related to the mass of (techni-) ρ\rho meson (MρM_\rho) and the decay constant (fπf_\pi) as ξfπzmfπ/Mρ\xi \sim f_\pi z_m \sim f_\pi/M_\rho for ξ1\xi \ll 1. However, although ξ\xi is related to the techni-fermion condensate \condense, we find no particular suppression of ξ\xi and hence of SS due to large γm\gamma_m, based on the correct identification of the renormalization-point dependence of \condense in contrast to the literature. Then we argue possible behaviors of fπ/Mρf_\pi/M_\rho as \condense \to 0 near the conformal window characterized by the Banks-Zaks infrared fixed point in more explicit dynamics with γm1\gamma_m \simeq 1. It is a curious coincidence that the result from ladder Schwinger-Dyson and Bethe-Salpeter equations well fits in the parameter space obtained in this paper. When fπ/Mρ0f_\pi/M_\rho \to 0 is realized, the holography suggests a novel possibility that fπf_\pi vanishes much faster than the dynamical mass mm does.Comment: typo, a version to be published in Progress of Theoretical Physic

    Holographic Techni-dilaton

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    Techni-dilaton, a pseudo-Nambu-Goldstone boson of scale symmetry, was predicted long ago in the Scale-invariant/Walking/Conformal Technicolor (SWC-TC) as a remnant of the (approximate) scale symmetry associated with the conformal fixed point, based on the conformal gauge dynamics of ladder Schwinger-Dyson (SD) equation with non-running coupling. We study the techni-dilaton as a flavor-singlet bound state of techni-fermions by including the techni-gluon condensate (tGC) effect into the previous (bottom-up) holographic approach to the SWC-TC, a deformation of the holographic QCD with γm0\gamma_m \simeq 0 by large anomalous dimension γm1\gamma_m \simeq 1. With including a bulk scalar field corresponding to the gluon condensate, we first improve the Operator Product Expansion of the current correlators so as to reproduce gluonic 1/Q41/Q^4 term both in QCD and SWC-TC. We find in QCD about 10%10\% (negative) contribution of gluon condensate to the ρ\rho meson mass. We also calculate the oblique electroweak SS-parameter in the presence of the effect of the tGC and find that for the fixed value of SS the tGC effects dramatically reduce the flavor-singlet scalar (techni-dilaton) mass MTDM_{\rm TD} (in the unit of FπF_\pi), while the vector and axial-vector masses MρM_\rho and Ma1M_{a_1} are rather insensitive to the tGC, where FπF_\pi is the decay constant of the techni-pion. If we use the range of values of tGC implied by the ladder SD analysis of the non-perturbative scale anomaly in the large NfN_f QCD near the conformal window, the phenomenological constraint S0.1S \simeq 0.1 predicts the techni-dilaton mass MTD600M_{\rm TD} \sim 600 GeV which is within reach of LHC discovery.Comment: 28 pages, 11 eps files, typos corrected, references added, Fig.1 corrected, some discussions added, to be published in PR

    Predictive Simulation for Surface Fault Occurrence Using High-Performance Computing

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    Numerical simulations based on continuum mechanics are promising methods for the estimation of surface fault displacements. We developed a parallel finite element method program to perform such simulations and applied the program to reproduce the 2016 Kumamoto earthquake, where surface rupture was observed. We constructed an analysis model of the 5 × 5 × 1 km domain, including primary and secondary faults, and inputted the slip distribution of the primary fault, which was obtained through inversion analysis and the elastic theory of dislocation. The simulated slips on the surface were in good agreement with the observations. We then conducted a predictive simulation by inputting the slip distributions of the primary fault, which were determined using a strong ground motion prediction method for an earthquake with a specified source fault. In this simulation, no surface slip was induced in the sub-faults. A large surface slip area must be established near a sub-fault to induce the occurrence of a slip on the surface

    Predictive Simulation for Surface Fault Occurrence Using High-Performance Computing

    No full text
    Numerical simulations based on continuum mechanics are promising methods for the estimation of surface fault displacements. We developed a parallel finite element method program to perform such simulations and applied the program to reproduce the 2016 Kumamoto earthquake, where surface rupture was observed. We constructed an analysis model of the 5 × 5 × 1 km domain, including primary and secondary faults, and inputted the slip distribution of the primary fault, which was obtained through inversion analysis and the elastic theory of dislocation. The simulated slips on the surface were in good agreement with the observations. We then conducted a predictive simulation by inputting the slip distributions of the primary fault, which were determined using a strong ground motion prediction method for an earthquake with a specified source fault. In this simulation, no surface slip was induced in the sub-faults. A large surface slip area must be established near a sub-fault to induce the occurrence of a slip on the surface
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