Using the most general form of the interpolating current of the heavy spin 1/2, $Σ_{b}$ baryon and distribution amplitudes of the nucleon, the transition form factors of the semileptonic $Σ_{b}\to Nlν$ decay are calculated in the framework of light cone QCD sum rules. It is obtained that the form factors satisfy the heavy quark effective theory relations. The obtained results for the related form factors are used to estimate the decay rate of this transition.
B_c mesons are laboratories for probing heavy quark physics. Furthermore, they decay into charmonia and hence their decays can be used to analyze possible exotic charmonium. In this work, the semileptonic decays of B_c mesons into P wave charmonia are analysed using light cone QCD sum rules (LCSR). The distributions amplitudes for the charmonia are taken from a quark model computation. The obtained decay rates for the ground state and excited charmonia are compared with the results found in the literature.
Light-cone QCD sum rules for the semileptonic decay Lambda_b --> p lepton anti-neutrino
在全QCD和HQET中,用光锥求和规则研究了唯一的半轻子重子衰变Λ_bPDMATHABMM p l \bar ν.计算描述衰减的形状因子,并用于预测衰减宽度和微分分布。由全QCD得到的总衰变宽度与以前的理论预测一致,而HQET结果通常要小一个数量级。这两个结果都与实验上限相一致,并可以与未来改进的实验数据进行比较。
Form factors of the weak $Ξ_c \to Ξ(Λ)$ transitions are calculated within the light cone QCD sum rules. The pollutions coming from the contribution of the negative parity $Ξ_c^*$ baryon is eliminated by considering the combinations of sum rules corresponding to the different Lorentz structures. Having obtained the form factors, the branching ratios of the $Ξ_c \to Ξ(Λ) \ell ν$ decays are also calculated, and our predictions are compared with the results of other approaches as well as the measurements done by BELLE and ALICE Collaborations.
In the $\rm SU(3)_F$ symmetry limit, using two- and three-particle distribution amplitudes of $B^{\pm}$-meson for $B_s$, the transition form factors of semileptonic $B_{s}\to K_{0}^*(1430)$ decays are calculated in the framework of the light-cone sum rules. The two-particle distribution amplitudes, $φ_{_{+}}(ω)$ and $φ_{_{-}}(ω)$ have the most important contribution in estimation of the form factors $f_{+}(q^2)$, $f_{-}(q^2)$ and $f_{T}(q^2)$. The knowledge of the behavior of $φ_{_+}(ω)$ is still rather limited. Therefore, we consider three different parametrizations for the shapes of $φ_{_+}(…
The weak decay process of $Ω_c$ to $Ξ$ is calculated in the method of QCD light-cone sum rule. The decay width of $Ω_c^0 \to Ξ^- l^+ ν_l$ and its decay branching ratio are also calculated with the form factors from this work's calculation. To the twist-6 distribution amplitudes, the form factors $f_1=0.66\pm0.02, f_2=-0.76\pm0.03, g_1=0.06\pm0.01$ and $g_2=-0.44\pm0.01$ are given at zero recoil point. The result of the semileptonic decay width of $Ω_c^0 \to Ξ^-l^+ν_l$ is $Γ=(7.51\pm0.36)\times10^{-15}~{\rm{GeV}}$ , and the prediction of the decay branching ratio $Br(Ω_c^0\toΞ^-l^+ν_l)=(3.06\pm…
Semileptonic decay processes of $Ξ_c \to Ξ\ellν_\ell$ are studied by light-cone QCD sum rules in this paper. The six form factors of $Ξ_c \to Ξ$ semileptonic transition matrix elements are calculated by this method with the light-cone distribution amplitudes of $Ξ$ baryon up to twist six. With the six form factors, the absolute branching ratios of $Ξ_c^0 \to Ξ^- \ell^+ ν_\ell$ and $Ξ_c^+ \to Ξ^0 \ell^+ ν_\ell$ are calculated by the helicity amplitudes formalism of semileptonic differential decay widths. The ratios of absolute branching ratios of electron and muon final states processes give th…
In this work, we analyze the semileptonic decay processes of $Λ_b \to Λ_c$ in the light-cone sum rule approach. In order to calculate the form factors of the $Λ_b$ baryon transition matrix element, we use the light-cone distribution amplitudes of $Λ_b$ obtained from the QCD sum rule in the heavy quark effective field theory framework. With the calculation of the six form factors of the $Λ_b \to Λ_c$ transition matrix element, the differential decay widths of $Λ_b^0 \to Λ_c^+ \ell^- \overlineν_\ell (\ell = e, ~μ, ~τ)$ and their absolute branching fractions are obtained. Additionally, the ratio …
Strong coupling constant of negative parity nucleon with $π$ meson in light cone QCD sum rules
在光锥QCD求和规则下,我们估计了负宇称核子与$π$介子之间的强耦合常数。本文提出了一种消除核子-核子和核子-负宇称核子跃迁中不需要的贡献的方法。我们观察到负宇称核子$N^\ast N^\ast π$跃迁的强耦合常数值与三点QCD求和规则所预言的有很大的差别,而与正宇称$N N π$跃迁的耦合常数值很接近.
We systematically study the semileptonic decay process of $ D\rightarrow S,A l\bar{ν_{l}}(l=e,μ)$ by light-cone sum rules (LCSR) with chiral currents, calculate the form factors containing only the contribution of the leading twist light-cone distribution amplitudes (LCDAs). For scalar mesons $a_{0}(980)$ and $a_{0}(1450)$, we take them as $q\bar{q}$ states. For axial-vector meson, we study $a_{1}(1260)( 1^{3}p^{1})$ and $b_{1}(1235)( 1^{1}p^{1})$. Based on the results of these form factors, we further present the branching ratios of these semileptonic decay processes. The numerical results fo…
Semileptonic decays $D_{(s)} \to η^{(\prime)} \ell^+ ν_\ell$ from QCD Light-Cone Sum Rules
School of Physics and Electronics, Hunan University(湖南大学物理与电子学院);School for Theoretical Physics, Hunan University(湖南大学理论物理学院);Hunan Provincial Key Laboratory of High-Energy Scale Physics and Applications(湖南省高能标物理与应用重点实验室)
Intrinsic strange distributions in the nucleon from the light-cone models
对核子中奇异夸克和反奇异夸克分布的精确认识是更好地理解强相互作用和核子结构的重要一步。此外,核子中的$ s-\bar s $不对称性在一些涉及强子的物理过程中起着重要的作用。本文的目的是研究核子奇异海的内禀奇异贡献。为此,我们计算了各种光锥模型,包括BHPS,标量五夸克模型和介子-重子模型的内禀奇异分布,并比较了它们的结果。这些模型可以导致在不同的$ x $值中占主导地位的内禀奇异的相当不同的分布。此外,介子-重子模型导致的$ s-\bar s $不对称性,可以在某些情况下从PDF的整体分析获得的结果进行比较。我们还提出了一个简单的参数化为每个模型预测的内在奇怪的分布。
We compare a non-factorizable charming-loop correction to an exclusive FCNC $B$-decay given in terms of the 3-particle Bethe-Salpeter amplitude (3BS) of the $B$-meson, $\langle 0|\bar q(x)G_{μν}(z)b(0)|B(p)\rangle$, with the corresponding correction to the $B$-meson semileptonic form factor. In spite of certain similarities, these two corrections are shown to have substantial differences: The form factor correction is dominated by the collinear light-cone configuration of 3BS: $z_μ= u x_μ$, $0 < u < 1$, $x^2=0$. In contrast, the FCNC amplitude is dominated by a different configuration with non…
Comparative analysis of the semileptonic $Λ_b \rightarrow Λ\ell^+ \ell^-$ transition in SM and different SUSY scenarios using form factors from full QCD