4,152 research outputs found

    Leptophilic dark matter in gauged U(1)LeLμU(1)_{L_e-L_\mu} model in light of DAMPE cosmic ray e++ee^+ + e^- excess

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    Motivated by the very recent cosmic-ray electron+positron excess observed by DAMPE collaboration, we investigate a Dirac fermion dark matter (DM) in the gauged LeLμL_e - L_\mu model. DM interacts with the electron and muon via the U(1)eμU(1)_{e-\mu} gauge boson ZZ^{'}. The model can explain the DAMPE data well. Although a non-zero DM-nucleon cross section is only generated at one loop level and there is a partial cancellation between ZeeZ^{'}ee and ZμμZ^{'}\mu\mu couplings, we find that a large portion of ZZ^{'} mass is ruled out from direct DM detection limit leaving the allowed ZZ^{'} mass to be close to two times of the DM mass. Implications for ppZ2pp \to Z^{'} \to 2\ell and pp2+Zpp \to 2\ell + Z^{'} , and muon g2g-2 anomaly are also studied.Comment: Discussions added, version accepted by EPJ

    Validation of the chinese version of the oral health impact profile for TMDs (OHIP- TMDs-C)

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    Objectives: The aim of this study was to evaluate the reliability and validity of the the Chinese version of the Oral Health Impact Profile for TMDs (OHIP-TMDs-C). Study Design: The OHIP-TMDs was initially translated and cross-culturally adapted to Chinese following international guidelines; then subsequently validated for the psychometric characteristics of reliability and validity. In total, 156 participants with temporomandibular disorders (TMDs) were recruited to complete the questionnaire. The reliability of the OHIP-TMDs-C was evaluated using internal consistency and test-retest methods. The validity of the OHIP-TMDs-C was analysed by construct validity and convergent validity. Construct validity was determined based on factor analysis, and convergent validity by analyzing the correlation between OHIP-TMDs-C subscale scores and the global rating of oral health question. Results: Cronbach’s alpha value (internal reliability) for the total OHIP-TMDs-C score was 0.917 and the intraclass correlation coefficient (ICC) value (test–retest reliability) was 0.899. Construct validity was determined by factor analysis, extracting five factors, accounting for 78.6% of the variance. All items had factor loadings above 0.40. In terms of convergent validity, the OHIP-TMDs-C subscale was significant correlated to the global oral health rating. Conclusions: The results suggest that the OHIP-TMDs-C has good reliability and validity and thus may be used as a valuable instrument for patients with TMDs in China

    CO J=3-2 Emission from the "Water Fountain" Sources IRAS 16342-3814 and IRAS 18286-0959

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    We observed CO J=3-2 emission from the "water fountain" sources, which exhibit high-velocity collimated stellar jets traced by water maser emission, with the Atacama Submillimeter Telescope Experiment (ASTE) 10 m telescope. We detected the CO emission from two sources, IRAS 16342-3814 and IRAS 18286-0959. The IRAS 16342-3814 CO emission exhibits a spectrum that is well fit to a Gaussian profile, rather than to a parabolic profile, with a velocity width (FWHM) of 158+/-6 km/s and an intensity peak at VLSR = 50+/-2 km/s. The mass loss rate of the star is estimated to be ~2.9x10^-5 M_sun/yr. Our morpho-kinematic models suggest that the CO emission is optically thin and associated with a bipolar outflow rather than with a (cold and relatively small) torus. The IRAS 18286-0959 CO emission has a velocity width (FWHM) of 3.0+/-0.2 km/s, smaller than typically seen in AGB envelopes. The narrow velocity width of the CO emission suggests that it originates from either an interstellar molecular cloud or a slowly-rotating circumstellar envelope that harbors the water maser source.Comment: 10 pages, 4 figure, accepted for publication in the Publications of the Astronomical Society of Japan, Vol. 61, No.6, 2009 December issu

    Information Geometry Theoretic Measures for Characterizing Neural Information Processing from Simulated EEG Signals

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    In this work, we explore information geometry theoretic measures for characterizing neural information processing from EEG signals simulated by stochastic nonlinear coupled oscillator models for both healthy subjects and Alzheimer’s disease (AD) patients with both eyes-closed and eyes-open conditions. In particular, we employ information rates to quantify the time evolution of probability density functions of simulated EEG signals, and employ causal information rates to quantify one signal’s instantaneous influence on another signal’s information rate. These two measures help us find significant and interesting distinctions between healthy subjects and AD patients when they open or close their eyes. These distinctions may be further related to differences in neural information processing activities of the corresponding brain regions, and to differences in connectivities among these brain regions. Our results show that information rate and causal information rate are superior to their more traditional or established information-theoretic counterparts, i.e., differential entropy and transfer entropy, respectively. Since these novel, information geometry theoretic measures can be applied to experimental EEG signals in a model-free manner, and they are capable of quantifying non-stationary time-varying effects, nonlinearity, and non-Gaussian stochasticity presented in real-world EEG signals, we believe that they can form an important and powerful tool-set for both understanding neural information processing in the brain and the diagnosis of neurological disorders, such as Alzheimer’s disease as presented in this work

    Systematic investigation of the rotational bands in nuclei with Z100Z \approx 100 using a particle-number conserving method based on a cranked shell model

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    The rotational bands in nuclei with Z100Z \approx 100 are investigated systematically by using a cranked shell model (CSM) with the pairing correlations treated by a particle-number conserving (PNC) method, in which the blocking effects are taken into account exactly. By fitting the experimental single-particle spectra in these nuclei, a new set of Nilsson parameters (κ\kappa and μ\mu) and deformation parameters (ε2\varepsilon_2 and ε4\varepsilon_4) are proposed. The experimental kinematic moments of inertia for the rotational bands in even-even, odd-AA and odd-odd nuclei, and the bandhead energies of the 1-quasiparticle bands in odd-AA nuclei, are reproduced quite well by the PNC-CSM calculations. By analyzing the ω\omega-dependence of the occupation probability of each cranked Nilsson orbital near the Fermi surface and the contributions of valence orbitals in each major shell to the angular momentum alignment, the upbending mechanism in this region is understood clearly.Comment: 21 pages, 24 figures, extended version of arXiv: 1101.3607 (Phys. Rev. C83, 011304R); added refs.; added Fig. 4 and discussions; Phys. Rev. C, in pres

    Plant diversity of Southeast Asia-II

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    The special issue of plant diversity in Southeast Asia will focus on the documentation of new discoveries in SE Asia. There are four global biodiversity hotspots in Southeast Asia. Although there are many plans to protect this rich biodiversity, however, the rich biodiversity in SE Asia is under threat due to economic development and population growth. There is a huge gap between our knowledge and biodiversity in SE Asia. During the last six investigations, many new taxa, including new species, new genera, have been discovered. This special issue will bring the rich but little known biodiversity to the public and protect them

    Energy Spectrum Theory of Incommensurate Systems

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    Due to the lack of the translational symmetry, calculating the energy spectrum of an incommensurate system has always been a theoretical challenge. Here, we propose a natural approach to generalize the energy band theory to the incommensurate systems without reliance on the commensurate approximation, thus providing a comprehensive energy spectrum theory of the incommensurate systems. Except for a truncation dependent weighting factor, the formulae of this theory are formally almost identical to that of the Bloch electrons, making it particularly suitable for complex incommensurate structures. To illustrate the application of this theory, we give three typical examples: one-dimensional bichromatic and trichromatic incommensurate potential model, as well as a moir\'{e} quasicrystal. Our theory establishes a fundamental framework for understanding the incommensurate systems.Comment: 7 pages, 3 figure
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