Flavor structure of Lambda baryons from lattice QCD - from strange to charm
Flavor structure of Lambda baryons from lattice QCD - from strange to charm
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来自晶格 QCD 的 Lambda 重子的味道结构 - 从奇怪到魅力
DOI：
10.1103/physrevd.94.114518
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发表时间：
2016
影响因子：
5
通讯作者：
Makoto Oka
中科院分区：
文献类型：
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作者：
Philipp Gubler;Toru T. Takahashi;Makoto Oka
我们研究了全味晶格QCD中具有奇异价夸克或魅力价夸克的自旋奇偶重子。多重子算符和八重子算符被用来在晶格上产生所需的单重子态。通过变分方法，这些态与不同算符的耦合提供了关于重子味道结构的信息。我们利用PACS-CS合作的规范组态，将质量和风味成分的结果手性外推到物理点。此外，我们还将最重夸克的跳跃参数从奇异逐渐改变为魅力，以研究重子的性质如何随重夸克质量的变化而演化。结果表明，重子能级几乎与夸克质量成线性关系。同时，大多数州的风味结构保持稳定，除了最低的州，它从单一风味转变为具有相同大小的单重态和八重态成分。最后，我们讨论了我们的发现是否可以用一个简单的夸克模型来解释，发现负的单晶可以很自然地解释为光和夸克的双夸克激发。另一方面，夸克模型的图像似乎不足以描述负单胞，这表明了用其他自由度来描述它们的重要性。
We studybaryons of spin-paritywith either a strange or charm valence quark in fullflavor lattice QCD. Multiplesinglet and octet operators are employed to generate the desired single baryon states on the lattice. Via the variational method, the couplings of these states to the different operators provide information about the flavor structure of thebaryons. We make use of the gauge configurations of the PACS-CS Collaboration and chirally extrapolate the results for the masses andflavor components to the physical point. We furthermore gradually change the hopping parameter of the heaviest quark from strange to charm to study how the properties of thebaryons evolve as a function of the heavy quark mass. It is found that the baryon energy levels increase almost linearly with the quark mass. Meanwhile, the flavor structure of most of the states remains stable, with the exception of the loweststate, which changes from a flavor singletto astate with singlet and octet components of comparable size. Finally, we discuss whether our findings can be interpreted with the help of a simple quark model and find that the negative-paritystates can be naturally explained as diquark excitations of the lightandquarks. On the other hand, the quark-model picture does not appear to be adequate for the negative-paritystates, suggesting the importance of other degrees of freedom to describe them.