论文标题
$ d \ to p（π，k）$ helicity formal formal sumbone sum规则方法
$D \to P(π,K)$ helicity form factors within light-cone sum rule approach
论文作者
论文摘要
在本文中，通过应用QCD轻单和规则（LCSR）方法研究了$ d \ to p（π，k）$螺旋形式颜色（HFF）。计算准确性最终达到扭曲分布幅度的近代领先顺序（NLO）Gluon辐射校正。最大后坐力点的最终HFF为$ {\ cal p} _ {t，0}^π（0）= 0.688^{+0.020} _ { - 0.024} $，$ {\ cal p} _ {\ cal p} _ {其中，来自领先顺序（LO）的三个粒子的贡献是如此之小，以至于可以安全地忽略，并且Nlo Gluon辐射校正对$ {\ cal p} _ {t，0}^，0}^{π，k}（0）$的最大贡献是小于$ 3 \％$。将这些HFF的LCSR预测推算为整个$ q^2 $ - 地区之后，我们获得了半衰减衰减过程的衰减宽度$ d \ to p \ellν_\ ell $，它们与错误的BES-III合作预测一致。在考虑了$ d^{+}/d^{0} $ - 梅森一生之后，我们将$ d \的分支分数提供给p \ellν_\ ell $，$ \ ell = e，μ$，我们的预测也同意bes-iii在错误的过程中，尤其是$ d \ to $ d \ to-d \ to-for-el el el el el el el el g el el g el Ell $ $ $ $ $ $ $ $ $ $ decay decay decay。最后，我们介绍前向后的不对称$ {\ cal a} _ {\ rm fb}^\ ell（q^2）$和Lepton convexity参数$ {\ cal c} _f^\ ell（q^2），并进一步计算了这些两个观察$ \ langle \ langle \ cal的平均值fb}^\ ell \ rangle $和$ \ langle {\ cal c} _f^\ ell \ rangle $，这可以提供一种在将来实验中测试这些HFF的方法。
In this paper, the $D\to P(π, K)$ helicity form factors (HFFs) are studied by applying the QCD light-cone sum rule (LCSR) approach. The calculation accuracy is up to next-to-leading order (NLO) gluon radiation correction of twist-(2,3) distribution amplitude. The resultant HFFs at large recoil point are ${\cal P}_{t,0}^π(0) = 0.688^{+0.020}_{-0.024}$, ${\cal P}_{t,0}^K(0)=0.780^{+0.024}_{-0.029}$. In which, the contributions from three particles of the leading order (LO) are so small that can be safely neglected, and the maximal contribution of the NLO gluon radiation correction for ${\cal P}_{t,0}^{π,K}(0)$ is less than $3\%$. After extrapolating the LCSR predictions for these HFFs to whole $q^2$-region, we obtain the decay widths for semileptonic decay processes $D\to P\ellν_\ell$, which are consistent with BES-III collaboration predictions within errors. After considering the $D^{+}/D^{0}$-meson lifetime, we give the branching fractions of $D\to P\ellν_\ell$ with $\ell = e, μ$, our predictions also agree with BES-III collaboration within errors, especially for $D\to π\ellν_\ell$ decay process. Finally, we present the forward-backward asymmetry ${\cal A}_{\rm FB}^\ell(q^2)$ and lepton convexity parameter ${\cal C}_F^\ell(q^2)$, and further calculate the mean value of these two observations $\langle{\cal A}_{\rm FB}^\ell\rangle$ and $\langle{\cal C}_F^\ell\rangle$, which may provide a way to test those HFFs in future experiments.
