Search for the possible S=+1 pentaquark states in quenched lattice QCD
Search for the possible S=+1 pentaquark states in quenched lattice QCD
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DOI：
10.1103/physrevd.71.114509
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发表时间：
2005-03
影响因子：
5
通讯作者：
Toru T. Takahashi;T. Umeda;T. Onogi;T. Kunihiro
中科院分区：
文献类型：
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作者：
Toru T. Takahashi;T. Umeda;T. Onogi;T. Kunihiro
我们研究了淬灭格点QCD中自旋为（1/2）的强子态，以寻找可能的S=+1五夸克态共振.在淬灭水平下，在8{sup 3} x24，10{sup 3}x24，12{sup 3}x24和16{sup 3}x24格点上，在β =5.7的条件下，采用标准格片规范作用量和Wilson夸克作用量进行了模拟.我们在时间方向上对夸克采用了Dirichlet边界条件，以避免由于夸克场的（反）周期边界条件而可能产生的污染，这是五夸克所特有的.通过对角化由量子数为（I，J）=（0，（1/2））的两个独立算符构成的2 × 2关联矩阵，我们成功地得到了该通道中最低态和第二最低态的能量.对能量和谱权因子的体积依赖性的分析表明，在（I，J{sup-}）=（0，（1/2）{sup -}）通道中，在略高于核子-K介子（NK）阈值的情况下，可能存在共振态.
We study spin (1/2) hadronic states in quenched lattice QCD to search for a possible S=+1 pentaquark resonance. Simulations are carried out on 8{sup 3}x24, 10{sup 3}x24, 12{sup 3}x24, and 16{sup 3}x24 lattices at {beta}=5.7 at the quenched level with the standard plaquette gauge action and the Wilson quark action. We adopt a Dirichlet boundary condition in the time direction for the quark to circumvent the possible contaminations due to the (anti)periodic boundary condition for the quark field, which are peculiar to the pentaquark. By diagonalizing the 2x2 correlation matrices constructed from two independent operators with the quantum numbers (I,J)=(0,(1/2)), we successfully obtain the energies of the lowest state and the 2nd-lowest state in this channel. The analysis of the volume dependence of the energies and spectral weight factors indicates that a resonance state is likely to exist slightly above the nucleon-Kaon (NK) threshold in (I,J{sup P})=(0,(1/2){sup -}) channel.