2,159 research outputs found

    Atomki anomaly and the Secluded Dark Sector

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    The Atomiki anomaly can be interpreted as a new light vector boson. If such a new particle exists, it could be a mediator between the Standard Model sector and the dark sector including the dark matter. We discussed some simple effective models with these particles. In the models, the secluded dark matter models are good candidates to satisfy the thermal relic abundance. In particular, we found that the dark matter self-interaction can be large enough to solve the small scale structure puzzles if the dark matter is a fermion.Comment: 5 pages, 4 figures, etc.; contribution to the proceedings of Joint Conference of ICGAC-XIII and IK15, Seoul, 3-7 July 2017; based on 1609.0160

    Unitarity Bounds on Dark Matter Effective Interactions at LHC

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    The perturbative unitarity bound is studied in the monojet process at LHC. The production of the dark matter is described by the low-energy effective theory. The analysis of the dark matter signal is not validated, if the unitarity condition is violated. It is shown that the current LHC analysis the effective theory breaks down, at least, when the dark matter is lighter than O(100) GeV. Future prospects for s\sqrt{s} = 14 TeV are also discussed. The result is independent of physics in high energy scales.Comment: 14 pages, 12 figures; v2: footnotes and references are added; figures are slightly change

    Current Status of Autoimmune Hepatitis in Japan

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    Autoimmune hepatitis (AIH) is a chronic and progressive disease characterized by histological interface hepatitis, hypergammaglobulinemia, and circulating autoantibodies. Multiple factors, including molecular mimicry, a genetic background including major histocompatibility complex class II, and defective function of regulatory T-cells, are involved in the pathogenesis. The diagnosis is made based on the scoring system of the International Autoimmune Hepatitis Group, the sensitivity and specificity of which are90%, respectively. AIH is classified into 3 sub-types based on the profiles of circulating autoantibodies: anti-nuclear antibody and/or smooth muscle antibody-positive (type 1), anti-liver-kidney microsomal antibody-positive (type 2), and anti-soluble liver antigen/liver-pancreas antigen antibody- positive (type 3). Recently, however, the number of atypical cases lacking the usual features has increased-for example, patients with acute-onset or fulminant-type AIH, autoantibody-negative patients, male patients, and patients with bile duct injury-and thus the clinical features of AIH have been diversified. AIH is responsive to immunosuppressive treatment in most cases; however, relapse occurs in more than 80% of patients within 1 year after immunosuppressive treatment withdrawal. The 10-year survival rate and the 10-year hepatocellular carcinoma-free rate are90%, respectively, indicating that some patients reach liver failure or develop hepatocellular carcinoma. To improve the prognosis of these patients, persistent normalization of transaminase is required.</p

    Trade impacts on skill formation: welfare improvements accompanied by rises in inequality

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    In this paper, we focus on the skill formation when considering the trade impacts on labor markets. Although workers are identical as unskilled labor, they differ in their productivity as skilled. Workers become skilled by incurring the training costs. Introducing the above settings into a trade model with monopolistic competition, we show that trade opening enhances skill formation. This is because trade enriches the varieties of differentiated goods and raises the utility of a worker for a given income. This effect works stronger for the skilled than for the unskilled although it makes all agents better off, leading to higher skill formation. However, it may be accompanied by rises in the real wage disparity between skilled and unskilled workers and by rises in the skilled wage inequality. Finally, we examine the possible effects of foreign direct investment on the labor market structure as well.trade, skill formation, monopolistic competition, wage inequality, FDI

    Probing new intra-atomic force with isotope shifts

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    In the development of atomic clocks, some atomic transition frequencies are measured with remarkable precision. These measured spectra may include effects of a new force mediated by a weakly interacting boson. Such effects might be distilled out from possible violation of a linear relation in isotope shifts between two transitions, as known as King's linearity, with relatively suppressed theoretical uncertainties. We discuss the experimental sensitivity to a new force in the test of the linearity as well as the linearity violation owing to higher order effects within the Standard Model. The sensitivity to new physics is limited by such effects. We have found that for Yb+^+, the higher order effect is in the reach of future experiments. The sensitivity to a heavy mediator is also discussed. It is analytically clarified that the sensitivity becomes weaker than that in the literature. Our numerical results of the sensitivity are compared with other weak force search experiments.Comment: 16 pages, 3 figures; published versio

    Structure of dimension-six derivative interactions in pseudo Nambu-Goldstone N Higgs doublet models

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    We derive the general structure of dimension-six derivative interactions in the N Higgs doublet models, where Higgs fields arise as pseudo Nambu-Goldstone modes of a strongly interacting sector. We show that there are several relations among the dimension-six operators, and therefore the number of independent operators decreases compared with models on which only SU(2)_L x U(1)_Y invariance is imposed. As an explicit example, we derive scattering amplitudes of longitudinal gauge bosons and Higgs bosons at high energy on models involving two Higgs doublets, and compare them with the amplitudes in the case of one Higgs doublet.Comment: 49 pages, 10 figure
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