15,838 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

    Which Type Of Work-Study Experience Is More Beneficial?: Perceptions Of Taiwanese College Students

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    The rapidly increase of tuition and the reduced financial support from government and families have forced many more students to take part-time jobs, however, different jobs might bear different benefits. The main purpose of this study were to identify the major benefits of part-time jobs or work-study experiences performed by college students, and to calculate the relative weight of each benefits perceived by students, and finally, to determine the most appropriate type of job for college students. A self-developed questionnaire is administered to 250 students from three universities. The results of this study not only help students to select the most appropriate types of job for a given purpose, but also provide school administrators with a guide to develop their student part-time job policies
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