3,745 research outputs found

    Reconstructing f(R) theory according to holographic dark energy

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    AbstractIn this Letter a connection between the holographic dark energy model and the f(R) theory is established. We treat the f(R) theory as an effective description for the holographic dark energy and reconstruct the function f(R) with the parameter c>1, c=1 and c<1, respectively. We show the distinctive behavior of each cases realized in f(R) theory, especially for the future evolution

    Production of doubly heavy baryons via Higgs boson decays

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    We systematically analyzed the production of semi-inclusive doubly heavy baryons (Ξcc\Xi_{cc}, Ξbc\Xi_{bc} and Ξbb\Xi_{bb}) for the process H0→ΞQQ′+Q′ˉ+QˉH^0 \rightarrow \Xi_{QQ'}+ \bar {Q'} + \bar {Q} through four main Higgs decay channels within the framework of non-relativistic QCD. The contributions from the intermediate diquark states, ⟨cc⟩[1S0]6\langle cc\rangle[^{1}S_{0}]_{\mathbf{6}}, ⟨cc⟩[3S1]3ˉ\langle cc\rangle[^{3}S_{1}]_{\mathbf{\bar 3}}, ⟨bc⟩[3S1]3ˉ/6\langle bc\rangle[^{3}S_{1}]_{\mathbf{\bar 3}/ \mathbf{6}}, ⟨bc⟩[1S0]3ˉ/6\langle bc\rangle[^{1}S_{0}]_{\mathbf{\bar 3}/ \mathbf{6}}, ⟨bb⟩[1S0]6\langle bb\rangle[^{1}S_{0}]_{\mathbf{6}} and ⟨bb⟩[3S1]3ˉ\langle bb\rangle[^{3}S_{1}]_{\mathbf{\bar 3}}, have been taken into consideration. The differential distributions and three main sources of the theoretical uncertainties have been discussed. At the High Luminosity Large Hadron Collider, there will be about 0.43×104\times10^4 events of Ξcc\Xi_{cc}, 6.32×104\times10^4 events of Ξbc\Xi_{bc} and 0.28×104\times10^4 events of Ξbb\Xi_{bb} produced per year. There are fewer events produced at the Circular Electron Positron Collider and the International Linear Collider, about 0.26×1020.26\times 10^{2} events of Ξcc\Xi_{cc}, 3.83×1023.83\times 10^{2} events of Ξbc\Xi_{bc} and 0.17×1020.17\times 10^{2} events of Ξbb\Xi_{bb} in operation.Comment: 15 pages, 3 figures, 7 table

    Renormalization group improved pQCD prediction for Υ(1S)\Upsilon(1S) leptonic decay

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    The complete next-to-next-to-next-to-leading order short-distance and bound-state QCD corrections to Υ(1S)\Upsilon(1S) leptonic decay rate Γ(Υ(1S)→ℓ+ℓ−)\Gamma(\Upsilon(1S)\to \ell^+\ell^-) has been finished by Beneke {\it et al.} \cite{Beneke:2014qea}. Based on those improvements, we present a renormalization group (RG) improved pQCD prediction for Γ(Υ(1S)→ℓ+ℓ−)\Gamma(\Upsilon(1S)\to \ell^+\ell^-) by applying the principle of maximum conformality (PMC). The PMC is based on RG-invariance and is designed to solve the pQCD renormalization scheme and scale ambiguities. After applying the PMC, all known-type of β\beta-terms at all orders, which are controlled by the RG-equation, are resummed to determine optimal renormalization scale for its strong running coupling at each order. We then achieve a more convergent pQCD series, a scheme- independent and more accurate pQCD prediction for Υ(1S)\Upsilon(1S) leptonic decay, i.e. ΓΥ(1S)→e+e−∣PMC=1.270−0.187+0.137\Gamma_{\Upsilon(1S) \to e^+ e^-}|_{\rm PMC} = 1.270^{+0.137}_{-0.187} keV, where the uncertainty is the squared average of the mentioned pQCD errors. This RG-improved pQCD prediction agrees with the experimental measurement within errors.Comment: 11 pages, 4 figures. Numerical results and discussions improved, references updated, to be published in JHE
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