$K^-d\rightarrow \pi\Sigma n$ reactions and structure of the $\Lambda(1405)$
$K^-d\rightarrow \pi\Sigma n$ reactions and structure of the $\Lambda(1405)$
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$K^-d ightarrow piSigma n$ 反应和 $Lambda(1405)$ 的结构
DOI：
10.1088/1742-6596/569/1/012077
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
W. Weise
中科院分区：
文献类型：
--
作者：
S. Ohnishi;Y. Ikeda;T. Hyodo;E. Hiyama;W. Weise
我们报道了K-d → π-n反应的杆KNN-πYN振幅的完整三体计算的第一个结果，并研究了Λ（1405）共振如何在K-d → π-n反应的中子能量分布中表现出来。振幅的计算使用的酒吧K NN-πYN耦合通道Alt-Grassberger-Sandhas（AGS）方程。考虑了两体介子-重子相互作用的两种模型：能量无关的相互作用和能量相关的相互作用，这两种模型都是由首阶手征SU（3）拉格朗日量导出的。这两个模型具有不同的离壳层性质，导致相应的不同行为的三体系统。结果表明，反映A（1405）质量分布和宽度的中子能谱对所用的（能量相关或能量无关）模型有很大的依赖性。因此，精确测量π介子的质量分布，就有可能区分出形成Λ（1405）的可能机制。
We report on the first results of a full three-body calculation of the bar K NN-πYN amplitude for the K− d→ πΣn reaction, and examine how the Λ (1405) resonance manifests itself in the neutron energy distributions of K− d→ πΣn reactions. The amplitudes are computed using the bar K NN-πYN coupled-channels Alt-Grassberger-Sandhas (AGS) equations. Two types of models are considered for the two-body meson-baryon interactions: an energy-independent interaction and an energy-dependent one, both derived from the leading order chiral SU (3) Lagrangian. These two models have different off-shell properties that cause correspondingly different behaviors in the three-body system. As a remarkable result of this investigation, it is found that the neutron energy spectrum, reflecting the A (1405) mass distribution and width, depends quite sensitively on the (energy-dependent or energy-independent) model used. Hence accurate measurements of the πΣ mass distribution have the potential to discriminate between possible mechanisms at work in the formation of the Λ (1405).