论文标题
$ d^{0} \ to k^{ - }π^{+}η$衰减的$ d^{0} \ dalitz分析
Dalitz analysis of $D^{0}\to K^{-}π^{+}η$ decays at Belle
论文作者
论文摘要
我们介绍了衰减$ d^{0} \的第一个dalitz图分析的结果，向k^{ - }π^{+}η$。该分析是对对应于953 $ \ rm {fb}^{ - 1} $ 953 $ \ rm的集成光度的数据集执行的。 Dalitz图通过六个共振衰减通道的组合进行很好地描述$ k^{*}（1680）^ - π^{+} $和$ k_2^{*}（1980）^ - π^{+} $，以及$kπ$和$kη$ s-s-wave组件。衰减$ k^{*}（1680）^{ - } \ to k^{ - }η$和$ k_ {2}^{*}（1980）^{ - } \ to k^{ - }η$首次观察到。我们测量分支分数的比率，$ \ frac {\ mathcal {b}（d^{0} \ to k^{ - }π^{+}}}} {\ Mathcal {b}（d^{0} \ to to k^{ - }π^{+}）} = 0.500 \ pm0.002 {\ rm（stat）} \ pm0.020 {\ rm（syst）} \ pm0.003 {\ rm（\ rm（\ mathcal {\ mathcal {b} _ {pdg} _ {pdg}）} $。使用dalitz fit结果，比率$ \ frac {\ mathcal {b}（k^{*}（1680）\ tokη）} {\ Mathcal {b}（k^{*}（k^{*}（1680）\ tokπ）} $ $ 0.11 \ pm0.02 {\ rm（stat）}^{+0.06} _ { - 0.04} {\ rm（syst）} \ pm0.04 {\ rm（\ mathcal {\ Mathcal {b} _这远低于在假设$ k^{*}（1680）$是纯$ 1^{3} d_1 $状态下的理论期望（$ \ of1 $）中。产品分支分数$ \ MATHCAL {B}（d^0 \ to [K_2^{*}（1980）^ - \ to K^{ - }η]π^{+}）=（2.2^{+1.7} _ { - 1.7} _ { - 1.9}）此外，$πη^{\ prime} $贡献了$ a_0（980）^{\ pm} $共振形状，使用三通道Flatté模型确认了10.1 $σ$统计显着性。我们还测量$ \ MATHCAL {B}（d^0 \ to \ bar {k}^{*}（892）^0η）=（1.41^{+0.13} _ { - 0.12}）\％$。这与当前世界平均$（1.02 \ pm0.30）\％$相一致，更精确，偏离显着性超过$3σ$的理论预测（0.51-0.92）％。
We present the results of the first Dalitz plot analysis of the decay $D^{0}\to K^{-}π^{+}η$. The analysis is performed on a data set corresponding to an integrated luminosity of 953 $\rm{fb}^{-1}$ collected by the Belle detector at the asymmetric-energy $e^{+}e^{-}$ KEKB collider. The Dalitz plot is well described by a combination of the six resonant decay channels $\bar{K}^{*}(892)^0η$, $K^{-}a_0(980)^+$, $K^{-}a_2(1320)^+$, $\bar{K}^{*}(1410)^0η$, $K^{*}(1680)^-π^{+}$ and $K_2^{*}(1980)^-π^{+}$, together with $Kπ$ and $Kη$ S-wave components. The decays $K^{*}(1680)^{-}\to K^{-}η$ and $K_{2}^{*}(1980)^{-}\to K^{-}η$ are observed for the first time. We measure ratio of the branching fractions, $\frac{\mathcal{B}(D^{0}\to K^{-}π^{+}η)}{\mathcal{B}(D^{0}\to K^{-}π^{+})}=0.500\pm0.002{\rm(stat)}\pm0.020{\rm(syst)}\pm0.003{\rm (\mathcal{B}_{PDG})}$. Using the Dalitz fit result, the ratio $\frac{\mathcal{B}(K^{*}(1680)\to Kη)}{\mathcal{B}(K^{*}(1680)\to Kπ)}$ is measured to be $0.11\pm0.02{\rm(stat)}^{+0.06}_{-0.04}{\rm(syst)}\pm0.04{\rm(\mathcal{B}_{\text{PDG}})}$; this is much lower than the theoretical expectations ($\approx1$) made under the assumption that $K^{*}(1680)$ is a pure $1^{3}D_1$ state. The product branching fraction $\mathcal{B}(D^0\to [K_2^{*}(1980)^-\to K^{-}η]π^{+})=(2.2^{+1.7}_{-1.9})\times10^{-4}$ is determined. In addition, the $πη^{\prime}$ contribution to the $a_0(980)^{\pm}$ resonance shape is confirmed with 10.1$σ$ statistical significance using the three-channel Flatté model. We also measure $\mathcal{B}(D^0\to\bar{K}^{*}(892)^0η)=(1.41^{+0.13}_{-0.12})\%$. This is consistent with, and more precise than, the current world average $(1.02\pm0.30)\%$, deviates with a significance of more than $3σ$ from the theoretical predictions of (0.51-0.92)%.
