2,480 research outputs found

    The ρ\rho-meson longitudinal leading-twist distribution amplitude

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    In the present paper, we suggest a convenient model for the vector ρ\rho-meson longitudinal leading-twist distribution amplitude ϕ2;ρ∥\phi_{2;\rho}^\|, whose distribution is controlled by a single parameter B2;ρ∥B^\|_{2;\rho}. By choosing proper chiral current in the correlator, we obtain new light-cone sum rules (LCSR) for the B→ρB\to\rho TFFs A1A_1, A2A_2 and VV, in which the δ1\delta^1-order ϕ2;ρ∥\phi_{2;\rho}^\| provides dominant contributions. Then we make a detailed discussion on the ϕ2;ρ∥\phi_{2;\rho}^\| properties via those B→ρB\to\rho TFFs. A proper choice of B2;ρ∥B^\|_{2;\rho} can make all the TFFs agree with the lattice QCD predictions. A prediction of ∣Vub∣|V_{\rm ub}| has also been presented by using the extrapolated TFFs, which indicates that a larger B2;ρ∥B^{\|}_{2;\rho} leads to a larger ∣Vub∣|V_{\rm ub}|. To compare with the BABAR data on ∣Vub∣|V_{\rm ub}|, the longitudinal leading-twist DA ϕ2;ρ∥\phi_{2;\rho}^\| prefers a doubly-humped behavior.Comment: 7 pages, 3 figures. Discussions improved and references updated. To be published in Phys.Lett.

    Revisiting the Pion Leading-Twist Distribution Amplitude within the QCD Background Field Theory

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    We study the pion leading-twist distribution amplitude (DA) within the framework of SVZ sum rules under the background field theory. To improve the accuracy of the sum rules, we expand both the quark propagator and the vertex (z\cdot \tensor{D})^n of the correlator up to dimension-six operators in the background field theory. The sum rules for the pion DA moments are obtained, in which all condensates up to dimension-six have been taken into consideration. Using the sum rules, we obtain \left|_{\rm 1\;GeV} = 0.338 \pm 0.032, \left|_{\rm 1\;GeV} = 0.211 \pm 0.030 and \left|_{\rm 1\;GeV} = 0.163 \pm 0.030. It is shown that the dimension-six condensates shall provide sizable contributions to the pion DA moments. We show that the first Gegenbauer moment of the pion leading-twist DA is a2π∣1  GeV=0.403±0.093a^\pi_2|_{\rm 1\;GeV} = 0.403 \pm 0.093, which is consistent with those obtained in the literature within errors but prefers a larger central value as indicated by lattice QCD predictions.Comment: 13 pages, 7 figure

    Insights into long noncoding RNAs of naked mole rat (Heterocephalus glaber) and their potential association with cancer resistance

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    Additional file 4: Table S3. Differential expressed lncRNAs identified in naked mole rat (Heterocephalus glaber) genome
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