15,202 research outputs found

    Masses of Scalar and Axial-Vector B Mesons Revisited

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    The SU(3) quark model encounters a great challenge in describing even-parity mesons. Specifically, the qqˉq\bar q quark model has difficulties in understanding the light scalar mesons below 1 GeV, scalar and axial-vector charmed mesons and 1+1^+ charmonium-like state X(3872)X(3872). A common wisdom for the resolution of these difficulties lies on the coupled channel effects which will distort the quark model calculations. In this work, we focus on the near mass degeneracy of scalar charmed mesons, Ds0∗D_{s0}^* and D0∗0D_0^{*0}, and its implications. Within the framework of heavy meson chiral perturbation theory, we show that near degeneracy can be qualitatively understood as a consequence of self-energy effects due to strong coupled channels. Quantitatively, the closeness of Ds0∗D_{s0}^* and D0∗0D_0^{*0} masses can be implemented by adjusting two relevant strong couplings and the renormalization scale appearing in the loop diagram. Then this in turn implies the mass similarity of Bs0∗B_{s0}^* and B0∗0B_0^{*0} mesons. The P0∗P1′P_0^* P'_1 interaction with the Goldstone boson is crucial for understanding the phenomenon of near degeneracy. Based on heavy quark symmetry in conjunction with corrections from QCD and 1/mQ1/m_Q effects, we obtain the masses of B(s)0∗B^*_{(s)0} and B(s)1′B'_{(s)1} mesons, for example, MBs0∗=(5715±1) MeV+δΔSM_{B_{s0}^*}= (5715\pm1)\,{\rm MeV}+\delta\Delta_S, MBs1′=(5763±1) MeV+δΔSM_{B'_{s1}}=(5763\pm1)\,{\rm MeV}+\delta\Delta_S with δΔS\delta\Delta_S being 1/mQ1/m_Q corrections. We find that the predicted mass difference of 48 MeV between Bs1′B'_{s1} and Bs0∗B_{s0}^* is larger than that of 20∼3020\sim 30 MeV inferred from the relativistic quark models, whereas the difference of 15 MeV between the central values of MBs1′M_{B'_{s1}} and MB1′M_{B'_1} is much smaller than the quark model expectation of 60−10060-100 MeV.Comment: 21 pages, 1 figure, to appear in Eur. Phys. J. (2017). arXiv admin note: text overlap with arXiv:1404.377

    Video Highlight Prediction Using Audience Chat Reactions

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    Sports channel video portals offer an exciting domain for research on multimodal, multilingual analysis. We present methods addressing the problem of automatic video highlight prediction based on joint visual features and textual analysis of the real-world audience discourse with complex slang, in both English and traditional Chinese. We present a novel dataset based on League of Legends championships recorded from North American and Taiwanese Twitch.tv channels (will be released for further research), and demonstrate strong results on these using multimodal, character-level CNN-RNN model architectures.Comment: EMNLP 201

    Investigation of the properties of nanostructured Li-doped NiO films using the modified spray pyrolysis method

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    The lithium-doped nickel oxide (L-NiO) films were synthetized using the modified spray pyrolysis method with a two-step grown process. By observing the spectra of X-ray photoemission spectroscopy of L-NiO films, the intensity of Ni 2p(3/2) peak of Ni(3+) bonding state increases with increasing Li concentration that causes the decrease of transparency and resistivity. The L-NiO films with optimum characteristics were obtained at Li = 8 at%, where a p-type resistivity of 4.1 × 10(−1) Ω cm and optical transparency above 76% in the visible region are achieved

    Developing the dielectric mechanisms of polyetherimide/multiwalled carbon nanotube/(Ba0.8Sr0.2)(Ti0.9Zr0.1)O3 composites

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    Various amounts of multiwalled carbon nanotubes [MWNTs] were embedded into polyetherimide [PEI] to form PEI/MWNT composites, and their dielectric properties were measured at 1 MHz. The Lichtenecker mixing rule was used to find a reasonable dielectric constant for the MWNTs used in this study. The dielectric constants of the developed composites were significantly increased, and the loss tangents were significantly decreased as 2.0 wt.% (Ba0.8Sr0.2)(Ti0.9Zr0.1)O3 ceramic powder [BSTZ] was added to the PEI/MWNTs to form PEI/MWNT/BSTZ composites. The Lichtenecker and Yamada mixing rules were used to predict the dielectric constants of the PEI/MWNT and PEI/MWNT/BSTZ composites. Equivalent electrical conduction models of both composites were established using the two mixing rules. In addition, the theoretical bases of the two mixing rules were used to explain the measured results for the PEI/MWNT and PEI/BSTZ/MWNT composites
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