Small eta-N scattering lengths favour eta-d and eta-alpha states
Small eta-N scattering lengths favour eta-d and eta-alpha states
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小 eta-N 散射长度有利于 eta-d 和 eta-alpha 态
DOI：
10.1088/0954-3899/32/8/007
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
B. K. Jain
中科院分区：
文献类型：
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作者：
N. Kelkar;K. Khemchandani;B. K. Jain
使用时间延迟方法预测的η介子和3 He核的不稳定状态被发现与最近由TAPS合作提出的η介子3 He状态的声明一致。在这里，我们扩展这种方法的推测性研究中发生的不稳定状态的eta-d和eta-4 He弹性散射。在有限秩近似（FRA）的少体方程的η-4 He散射的T-矩阵的评估。对于评估的时间延迟的η-d的情况下，我们使用现有的Faddeev计算的参数化，并比较从FRA获得的结果。当η-N散射长度为$a_{\eta N} =（0.42，0.34）$ fm时，在Faddeev计算范围内，我们发现了一个η-d不稳定的束缚态。对于较低的a_{\eta N}$，即a_{\eta N} =（0.28，0.19）$ fm，在FRA内发现类似的状态。接近阈值的eta-4 He不稳定束缚态的存在通过$a_{\eta N} =（0.28，0.19）$ fm暗示，但被大的散射长度排除。
Unstable states of the eta meson and the 3He nucleus predicted using the time delay method were found to be in agreement with a recent claim of eta-mesic 3He states made by the TAPS collaboration. Here, we extend this method to a speculative study of the unstable states occurring in the eta-d and eta-4He elastic scattering. The T-matrix for eta-4He scattering is evaluated within the Finite Rank Approximation (FRA) of few body equations. For the evaluation of time delay in the eta-d case, we use a parameterization of an existing Faddeev calculation and compare the results with those obtained from FRA. With an eta-N scattering length, $a_{\eta N} = (0.42, 0.34)$ fm, we find an eta-d unstable bound state around -16 MeV, within the Faddeev calculation. A similar state within the FRA is found for a low value of $a_{\eta N}$, namely, $a_{\eta N} = (0.28, 0.19)$ fm. The existence of an eta-4He unstable bound state close to threshold is hinted by $a_{\eta N} = (0.28, 0.19)$ fm, but is ruled out by large scattering lengths.