2,193 research outputs found

    Coupled-Channel-Induced Sβˆ’DS-D mixing of Charmonia and Testing Possible Assignments for Y(4260)Y(4260) and Y(4360)Y(4360)

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    The mass spectrum and the two-body open-charm decays of the JPC=1βˆ’βˆ’J^{PC}=1^{--} charmonium states are studied with the coupled-channel effects taken into account. The coupled-channel-induced mixing effects among the excited vector charmonia are studied. Based on our calculations of the masses and the decay widths, we find that the tension between the observed properties of Y(4260)/Y(4360)Y(4260)/Y(4360) and their conventional charmonia interpretations could be softened.Comment: 13 pages, 5 figures, 5 table

    Annihilation Rates of Heavy 1βˆ’βˆ’1^{--} S-wave Quarkonia in Salpeter Method

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    The annihilation rates of vector 1βˆ’βˆ’1^{--} charmonium and bottomonium 3S1^3S_1 states Vβ†’e+eβˆ’V \rightarrow e^+e^- and Vβ†’3Ξ³V\rightarrow 3\gamma, Vβ†’Ξ³ggV \rightarrow \gamma gg and Vβ†’3gV \rightarrow 3g are estimated in the relativistic Salpeter method. We obtained Ξ“(J/Οˆβ†’3Ξ³)=6.8Γ—10βˆ’4\Gamma(J/\psi\rightarrow 3\gamma)=6.8\times 10^{-4} keV, Ξ“(ψ(2S)β†’3Ξ³)=2.5Γ—10βˆ’4\Gamma(\psi(2S)\rightarrow 3\gamma)=2.5\times 10^{-4} keV, Ξ“(ψ(3S)β†’3Ξ³)=1.7Γ—10βˆ’4\Gamma(\psi(3S)\rightarrow 3\gamma)=1.7\times 10^{-4} keV, Ξ“(Ξ₯(1S)β†’3Ξ³)=1.5Γ—10βˆ’5\Gamma(\Upsilon(1S)\rightarrow 3\gamma)=1.5\times 10^{-5} keV, Ξ“(Ξ₯(2S)β†’3Ξ³)=5.7Γ—10βˆ’6\Gamma(\Upsilon(2S)\rightarrow 3\gamma)=5.7\times 10^{-6} keV, Ξ“(Ξ₯(3S)β†’3Ξ³)=3.5Γ—10βˆ’6\Gamma(\Upsilon(3S)\rightarrow 3\gamma)=3.5\times 10^{-6} keV and Ξ“(Ξ₯(4S)β†’3Ξ³)=2.6Γ—10βˆ’6\Gamma(\Upsilon(4S)\rightarrow 3\gamma)=2.6\times 10^{-6} keV. In our calculations, special attention is paid to the relativistic correction, which is important and can not be ignored for excited 2S2S, 3S3S and higher excited states.Comment: 10 pages,2 figures, 5 table

    The rare semi-leptonic BcB_c decays involving orbitally excited final mesons

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    The rare processes Bcβ†’D(s)J(βˆ—)ΞΌΞΌΛ‰B_c\to D_{(s)J} ^{(*)}\mu\bar{\mu}, where D(s)J(βˆ—)D_{(s)J}^{(*)} stands for the final meson Ds0βˆ—(2317)D_{s0}^*(2317), Ds1(2460,2536)D_{s1}(2460,2536),~Ds2βˆ—(2573)D_{s2}^*(2573), D0βˆ—(2400)D_0^*(2400), D1(2420,2430)D_{1}(2420,2430) or~D2βˆ—(2460)D_{2}^*(2460), are studied within the Standard Model. The hadronic matrix elements are evaluated in the Bethe-Salpeter approach and furthermore a discussion on the gauge-invariant condition of the annihilation hadronic currents is presented. Considering the penguin, box, annihilation, color-favored cascade and color-suppressed cascade contributions, the observables dBr/dQ2\text{d}Br/\text{d}Q^2, ALPLA_{LPL}, AFBA_{FB} and PLP_L are calculated

    Two-Body Strong Decay of Z(3930) as the Ο‡c2(2P)\chi_{c2} (2P) State

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    The new particle Z(3930) found by the Belle and BaBar Collaborations through the Ξ³Ξ³β†’DDΛ‰\gamma\gamma\rightarrow D\bar D process is identified to be the Ο‡c2(2P)\chi_{c2}(2P) state. Since the mass of this particle is above the DDΛ‰(βˆ—)D\bar D^{(\ast)} threshold, the OZI-allowed two-body strong decays are the main decay modes. In this paper, these strong decay modes are studied with two methods. One is the instantaneous Bethe-Salpeter method within Mandelstam formalism. The other is the combination of the 3P0^3P_0 model and the former formalism. The total decay widths are 26.3 and 27.3 MeV for the methods with or without the 3P0^3P_0 vertex, respectively. The ratio of Ξ“DDΛ‰\Gamma_{D\bar D} over Ξ“DDΛ‰βˆ—\Gamma_{D\bar D^\ast} which changes along with the mass of the initial meson is also presented.Comment: 11 pages, 3 figure

    Semi-leptonic and Non-leptonic BB meson decays to charmed mesons

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    We study the semi-leptonic and non-leptonic BB weak decays which are governed by the Bβ†’D(βˆ—)B\rightarrow D^{(*)} transitions. The branching ratios, CP asymmetries (CPA) and polarization fractions (FA) of non-leptonic decays are investigated in the factorization approximation. The Bβ†’D(βˆ—)B\rightarrow D^{(*)} form factors are estimated in the Salpeter method. Our estimation on branching ratios generally agree with the existent experimental data. For CPA and polarizations, comparisons among the FA results, the perturbative QCD predictions and experimental data are made.Comment: 8 pages, 1 figures, 5 table
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