1,359 research outputs found

    Electric Dipole Moments of Dyon and `Electron'

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    The electric and magnetic dipole moments of dyon fermions are calculated within N=2 supersymmetric Yang-Mills theory including the theta-term. It is found, in particular, that the gyroelectric ratio deviates from the canonical value of 2 for the monopole fermion (n_m=1,n_e=0) in the case theta\not=0. Then, applying the S-duality transformation to the result for the dyon fermions, we obtain an explicit prediction for the electric dipole moment (EDM) of the charged fermion (`electron'). It is thus seen that the approach presented here provides a novel method for computing the EDM induced by the theta-term.Comment: 16pages, no figures, PTPTeX, typos corrected, published versio

    Yukawa hierarchy from extra dimensions and infrared fixed points

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    We discuss the existence of hierarchy of Yukawa couplings in the models with extra spatial dimensions. The hierarchical structure is induced by the power behavior of the cutoff dependence of the evolution equations which yield large suppressions of couplings at the compactification scale. The values of coupling constants at this scale can be made stable almost independently of the initial input parameters by utilizing the infrared fixed point. We find that the Yukawa couplings converge to the fixed points very quickly because of the enhanced energy dependence of the suppression factor from extra dimensions as well as in the case of large gauge couplings at high-energy scale.Comment: 13 pages, 3 eps figure

    One-Face Shortest Disjoint Paths with a Deviation Terminal

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    k and the sum of their lengths is minimized. This problem is a natural optimization version of the well-known k-disjoint paths problem, and its polynomial solvability is widely open. One of the best results on the shortest k-disjoint paths problem is due to Datta et al. [Datta et al., 2018], who present a polynomial-time algorithm for the case when G is planar and all the terminals are on one face. In this paper, we extend this result by giving a polynomial-time randomized algorithm for the case when all the terminals except one are on some face of G. In our algorithm, we combine the arguments of Datta et al. with some results on the shortest disjoint (A + B)-paths problem shown by Hirai and Namba [Hirai and Namba, 2018]. To this end, we present a non-trivial bijection between k disjoint paths and disjoint (A + B)-paths, which is a key technical contribution of this paper

    SIMPLE RIBBON MOVES FOR LINKS

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    The physics of the mean and oscillating radial electric field in the L–H transition: the driving nature and turbulent transport suppression mechanism

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    The low-to-high confinement mode transition (L–H transition) is one of the key elements in achieving a self-sustained burning fusion reaction. Although there is no doubt that the mean and/or oscillating radial electric field plays a role in triggering and sustaining the edge transport barrier, the detailed underlying physics are yet to be unveiled. In this special topic paper, the remarkable progress achieved in recent years is reviewed for two different aspects: (i) the radial electric field driving procedure and (ii) the turbulent transport suppression mechanism. Experimental observations in different devices show possible conflicting natures for these phenomena, which cannot be resolved solely by conventional paradigms. New insights obtained by combining different model concepts successfully reconcile these conflicts
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