11,884 research outputs found

    The analysis of the charmonium-like states Xβˆ—(3860)X^{*}(3860),X(3872)X(3872), X(3915)X(3915), X(3930)X(3930) and X(3940)X(3940) according to its strong decay behaviors

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    Inspired by the newly observed state Xβˆ—(3860)X^{*}(3860), we analyze the strong decay behaviors of some charmonium-like states Xβˆ—(3860)X^{*}(3860),X(3872)X(3872), X(3915)X(3915), X(3930)X(3930) and X(3940)X(3940) by the 3P0^{3}P_{0} model. We carry out our work based on the hypothesis that these states are all being the charmonium systems. Our analysis indicates that 0++0^{++} charmonium state can be a good candidate for Xβˆ—(3860)X^{*}(3860) and 1++1^{++} state is the possible assignment for X(3872)X(3872). Considering as the 31S03^{1}S_{0} state, the decay behavior of X(3940)X(3940) is inconsistent with the experimental data. So, we can not assign X(3940)X(3940) as the 31S03^{1}S_{0} charmonium state by present work. Besides, our analysis imply that it is reasonable to assign X(3915)X(3915) and X(3930)X(3930) to be the same state, 2++2^{++}. However, combining our analysis with that of Zhou~\cite{ZhouZY}, we speculate that X(3915)X(3915)/X(3930)X(3930) might not be a pure ccβ€Ύc\overline{c} systems

    Strong coupling constants and radiative decays of the heavy tensor mesons

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    In this article, we analyze tensor-vector-pseudoscalar(TVP) type of vertices D2βˆ—+D+ρD_{2}^{*+}D^{+}\rho, D2βˆ—0D0ρD_{2}^{*0}D^{0}\rho, D2βˆ—+D+Ο‰D_{2}^{*+}D^{+}\omega, D2βˆ—0D0Ο‰D_{2}^{*0}D^{0}\omega, B2βˆ—+B+ρB_{2}^{*+}B^{+}\rho, B2βˆ—0B0ρB_{2}^{*0}B^{0}\rho, B2βˆ—+B+Ο‰B_{2}^{*+}B^{+}\omega, B2βˆ—0B0Ο‰B_{2}^{*0}B^{0}\omega, Bs2βˆ—BsΟ•B_{s2}^{*}B_{s}\phi and Ds2βˆ—DsΟ•D_{s2}^{*}D_{s}\phi, in the frame work of three point QCD sum rules. According to these analysis, we calculate their strong form factors which are used to fit into analytical functions of Q2Q^{2}. Then, we obtain the strong coupling constants by extrapolating these strong form factors into deep time-like regions. As an application of this work, the coupling constants for radiative decays of these heavy tensor mesons are also calculated at the point of Q2=0Q^{2}=0. With these coupling constants, we finally calculate the radiative decay widths of these tensor mesons.Comment: arXiv admin note: text overlap with arXiv:1810.0597

    Indirect unitarity violation entangled with matter effects in reactor antineutrino oscillations

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    If finite but tiny masses of the three active neutrinos are generated via the canonical seesaw mechanism with three heavy sterile neutrinos, the 3\times 3 Pontecorvo-Maki-Nakagawa-Sakata neutrino mixing matrix V will not be exactly unitary. This kind of indirect unitarity violation can be probed in a precision reactor antineutrino oscillation experiment, but it may be entangled with terrestrial matter effects as both of them are very small. We calculate the probability of \overline{\nu}_e \to \overline{\nu}_e oscillations in a good analytical approximation, and find that, besides the zero-distance effect, the effect of unitarity violation is always smaller than matter effects, and their entanglement does not appear until the next-to-leading-order oscillating terms are taken into account. Given a 20-kiloton JUNO-like liquid scintillator detector, we reaffirm that terrestrial matter effects should not be neglected but indirect unitarity violation makes no difference, and demonstrate that the experimental sensitivities to the neutrino mass ordering and a precision measurement of \theta_{12} and \Delta_{21} \equiv m^2_2 - m^2_1 are robust.Comment: 21 pages, 6 figures, version to be published in PLB, more discussions adde

    Analysis of the strong coupling form factors of Ξ£bNB\Sigma_bNB and Ξ£cND\Sigma_c ND in QCD sum rules

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    In this article, we study the strong interaction of the vertexes Ξ£bNB\Sigma_bNB and Ξ£cND\Sigma_c ND using the three-point QCD sum rules under two different dirac structures. Considering the contributions of the vacuum condensates up to dimension 55 in the operation product expansion, the form factors of these vertexes are calculated. Then, we fit the form factors into analytical functions and extrapolate them into time-like regions, which giving the coupling constant. Our analysis indicates that the coupling constant for these two vertexes are GΞ£bNB=0.43Β±0.01GeVβˆ’1G_{\Sigma_bNB}=0.43\pm0.01GeV^{-1} and GΞ£cND=3.76Β±0.05GeVβˆ’1G_{\Sigma_cND}=3.76\pm0.05GeV^{-1}.Comment: 6 figure

    Analysis of the charmed mesons D1βˆ—(2680)D_{1}^{*}(2680), D3βˆ—(2760)D_{3}^{*}(2760) and D2βˆ—(3000)D_{2}^{*}(3000)

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    In this work, we systematically study the strong decay behaviors of the charmed mesons D1βˆ—(2680)D_{1}^{*}(2680), D3βˆ—(2760)D_{3}^{*}(2760) and D2βˆ—(3000)D_{2}^{*}(3000) reported by the LHCb collaboration. By comparing the masses and the decay properties with the results of the experiment, we assigned these newly observed mesons as the 2S121βˆ’2S\frac{1}{2}1^{-}, 1D523βˆ’1D\frac{5}{2}3^{-} and 1F522+1F\frac{5}{2}2^{+} states respectively. As a byproduct, we also study the strong decays of the unobserved 2P322+2P\frac{3}{2}2^{+} and 2F522+2F\frac{5}{2}2^{+} charmed mesons, which is helpful to the future experiments in searching for these charmed mesons.Comment: arXiv admin note: text overlap with arXiv:0803.0106 by other author
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