6,658 research outputs found

    Edge-Fault Tolerance of Hypercube-like Networks

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    This paper considers a kind of generalized measure Ξ»s(h)\lambda_s^{(h)} of fault tolerance in a hypercube-like graph GnG_n which contain several well-known interconnection networks such as hypercubes, varietal hypercubes, twisted cubes, crossed cubes and M\"obius cubes, and proves Ξ»s(h)(Gn)=2h(nβˆ’h)\lambda_s^{(h)}(G_n)= 2^h(n-h) for any hh with 0β©½hβ©½nβˆ’10\leqslant h\leqslant n-1 by the induction on nn and a new technique. This result shows that at least 2h(nβˆ’h)2^h(n-h) edges of GnG_n have to be removed to get a disconnected graph that contains no vertices of degree less than hh. Compared with previous results, this result enhances fault-tolerant ability of the above-mentioned networks theoretically

    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
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