617 research outputs found

    Cosmologically safe QCD axion as a present from extra dimension

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    We propose a QCD axion model where the origin of PQ symmetry and suppression of axion isocurvature perturbations are explained by introducing an extra dimension. Each extra quark-antiquark pair lives on branes separately to suppress PQ breaking operators. The size of the extra dimension changes after inflation due to an interaction between inflaton and a bulk scalar field, which implies that the PQ symmetry can be drastically broken during inflation to suppress undesirable axion isocurvature fluctuations.Comment: 6 page

    Diphoton Excess as a Hidden Monopole

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    We provide a theory with a monopole of a strongly-interacting hidden U(1) gauge symmetry that can explain the 750-GeV diphoton excess reported by ATLAS and CMS. The excess results from the resonance of monopole, which is produced via gluon fusion and decays into two photons. In the low energy, there are only mesons and a monopole in our model because any baryons cannot be gauge invariant in terms of strongly interacting Abelian symmetry. This is advantageous of our model because there is no unwanted relics around the BBN epoch.Comment: 6 pages, 1 figur

    Unification of the Standard Model and Dark Matter Sectors in [SU(5)×\timesU(1)]4^4

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    A simple model of dark matter contains a light Dirac field charged under a hidden U(1) gauge symmetry. When a chiral matter content in a strong dynamics satisfies the t'Hooft anomaly matching condition, a massless baryon is a natural candidate of the light Dirac field. One realization is the same matter content as the standard SU(5)×\timesU(1)(BL)_{(B-L)} grand unified theory. We propose a chiral [SU(5)×\timesU(1)]4^4 gauge theory as a unified model of the SM and DM sectors. The low-energy dynamics, which was recently studied, is governed by the hidden U(1)4_4 gauge interaction and the third-family U(1)(BL)3_{(B-L)_3} gauge interaction. This model can realize self-interacting dark matter and alleviate the small-scale crisis of collisionless cold dark matter in the cosmological structure formation. The model can also address the semi-leptonic BB-decay anomaly reported by the LHCb experiment.Comment: 15 pages, 2 figure

    Abundance of microRNA target motifs in the 3′-UTRs of 20527 human genes

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    AbstractA mechanism, selective avoidance, proposes that microRNA (miRNA) target sites are selectively depleted in the 3′-UTRs of genes expressed at the same time and place as a miRNA. If this mechanism is ubiquitous, the target motif occurrences in the 3′-UTRs would be decreased. To test this hypothesis, we examined miRNA target motif occurrences in the 3′- and 5′-UTRs of 20527 human protein-coding genes. The results revealed that miRNA target motifs appeared more frequently than non-target motifs and were enriched in the 3′-UTRs. This enrichment was relatively reduced in a set of 2525 genes coexpressed with miR-124a in the prefrontal cortex, but still remained at a high level, suggesting that miRNA target motifs are fostered by some other factors that surpass the influence of selective avoidance

    Unification for the Darkly Charged Dark Matter

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    We provide a simple UV theory for a Dirac dark matter with a massless Abelian gauge boson. We introduce a single fermion transforming as the 16\bf{16} representation in the SO(10)' gauge group, which is assumed to be spontaneously broken to SU(5)×'\timesU(1)'. The SU(5)' gauge interaction becomes strong at an intermediate scale and then we obtain a light composite Dirac fermion with U(1)' gauge interaction at the low-energy scale. Its thermal relic can explain the observed amount of dark matter consistently with other cosmological and astrophysical constraints. We discuss that a nonzero kinetic mixing between the U(1)' gauge boson and the Hypercharge gauge boson is allowed and the temperature of the visible sector and the dark matter sector can be equal to each other.Comment: 6 pages, 2 figure

    Self-interacting dark matter with a vector mediator: kinetic mixing with U(1)(BL)3_{(B-L)_3} gauge boson

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    A spontaneously broken hidden U(1)h_h gauge symmetry can explain both the dark matter stability and the observed relic abundance. In this framework, the light gauge boson can mediate the strong dark matter self-interaction, which addresses astrophysical observations that are hard to explain in collisionless cold dark matter. Motivated by flavoured grand unified theories, we introduce right-handed neutrinos and a flavoured BLB - L gauge symmetry for the third family U(1)(BL)3_{(B-L)_3}. The unwanted relic of the U(1)h_h gauge boson decays into neutrinos via the kinetic mixing with the U(1)(BL)3_{(B - L)_3} gauge boson. Indirect detection bounds on dark matter are systematically weakened, since dark matter annihilation results in neutrinos. However, the kinetic mixing between U(1)(BL)3_{(B - L)_3} and U(1)Y_Y gauge bosons are induced by quantum corrections and leads to an observable signal in direct and indirect detection experiments of dark matter. This model can also explain the baryon asymmetry of the Universe via the thermal leptogenesis. In addition, we discuss the possibility of explaining the lepton flavour universality violation in semi-leptonic BB meson decays that is recently found in the LHCb experiment.Comment: 27 pages, 2 figures; v2: minor changes, Appendix A added, published versio

    Preventive Effect of Boiogito on Metabolic Disorders in the TSOD Mouse, a Model of Spontaneous Obese Type II Diabetes Mellitus

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    “Boiogito” is a Kampo preparation which has been used since ancient times in patients with obesity of the “asthenic constitution” type, so-called “watery obesity”, and its effect has been recognized clinically. In this study, we investigated the anti-obesity effect of Boiogito in the TSOD (Tsumura Suzuki Obese Diabetes) mouse, a model of spontaneous obese type II diabetes mellitus. Boiogito showed a significant anti-obesity effect in TSOD mice by suppressing body weight gain in a dosage-dependent manner. In addition, Boiogito showed significant ameliorative effects on features of metabolic syndrome such as hyperinsulinemia, fasting hyperglycemia and abnormal lipid metabolism. Regarding lipid accumulation in TSOD mice, Boiogito showed a significant suppressive effect on accumulation of subcutaneous fat, but the effect on the visceral fat accumulation that constitutes the basis of metabolic syndrome was weak, and the suppressive effect on insulin resistance was also weak. Furthermore, Boiogito did not alleviate the abnormal glucose tolerance, the hypertension or the peripheral neuropathy characteristically developed in the TSOD mice. In contrast, in the TSNO (Tsumura Suzuki Non-Obesity) mice used as controls, Boiogito suppressed body weight gain and accumulation of subcutaneous and visceral fat. The above results suggested that Boiogito is effective as an anti-obesity drug against obesity of the “asthenic constitution” type in which subcutaneous fat accumulates, but cannot be expected to exert a preventive effect against various symptoms of metabolic syndrome that are based on visceral fat accumulation
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