18,588 research outputs found

    Masses and decay constants of the heavy tensor mesons with QCD sum rules

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    In this article, we calculate the contributions of the vacuum condensates up to dimension-6 in the operator product expansion, study the masses and decay constants of the heavy tensor mesons D2βˆ—(2460)D_2^*(2460), Ds2βˆ—(2573)D_{s2}^*(2573), B2βˆ—(5747)B_2^*(5747), Bs2βˆ—(5840)B_{s2}^*(5840) using the QCD sum rules. The predicted masses are in excellent agreement with the experimental data, while the ratios of the decay constants fDs2βˆ—fD2βˆ—β‰ˆfBs2βˆ—fB2βˆ—β‰ˆfDsfD∣exp\frac{f_{D_{s2}^*}}{f_{D_{2}^*}}\approx\frac{f_{B_{s2}^*}}{f_{B_{2}^*}}\approx\frac{f_{D_{s}}}{f_{D}}\mid_{\rm exp}, where the exp denotes the experimental value.Comment: 13 pages, 13 figure

    Analysis of the DDΛ‰βˆ—KD\bar{D}^*K system with QCD sum rules

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    In this article, we construct the color singlet-singlet-singlet interpolating current with I(JP)=32(1βˆ’)I\left(J^P\right)=\frac{3}{2}\left(1^-\right) to study the DDΛ‰βˆ—KD\bar{D}^*K system through QCD sum rules approach. In calculations, we consider the contributions of the vacuum condensates up to dimension-16 and employ the formula ΞΌ=MX/Y/Z2βˆ’(2Mc)2\mu=\sqrt{M_{X/Y/Z}^{2}-\left(2{\mathbb{M}}_{c}\right)^{2}} to choose the optimal energy scale of the QCD spectral density. The numerical result MZ=4.71βˆ’0.11+0.19 GeVM_Z=4.71_{-0.11}^{+0.19}\,\rm{GeV} indicates that there exists a resonance state ZZ lying above the DDΛ‰βˆ—KD\bar{D}^*K threshold to saturate the QCD sum rules. This resonance state ZZ may be found by focusing on the channel J/ΟˆΟ€KJ/\psi \pi K of the decay B⟢J/ΟˆΟ€Ο€KB\longrightarrow J/\psi \pi \pi K in the future.Comment: 9 pages, 4 figure

    Complexity growth rates for AdS black holes in massive gravity and f(R)f(R) gravity

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    The "complexity = action" duality states that the quantum complexity is equal to the action of the stationary AdS black holes within the Wheeler-DeWitt patch at late time approximation. We compute the action growth rates of the neutral and charged black holes in massive gravity and the neutral, charged and Kerr-Newman black holes in f(R)f(R) gravity to test this conjecture. Besides, we investigate the effects of the massive graviton terms, higher derivative terms and the topology of the black hole horizon on the complexity growth rate.Comment: 11 pages, no figur
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