Light meson electromagnetic form factors from three-flavor lattice QCD with exact chiral symmetry
Light meson electromagnetic form factors from three-flavor lattice QCD with exact chiral symmetry
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DOI：
10.1103/physrevd.93.034504
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发表时间：
2015-10
影响因子：
5
通讯作者：
J. C. S. Aoki;G. Cossu;X. Feng;S. Hashimoto;T. Kaneko;J. Noaki;T. Onogi
中科院分区：
文献类型：
--
作者：
J. C. S. Aoki;G. Cossu;X. Feng;S. Hashimoto;T. Kaneko;J. Noaki;T. Onogi
研究了三味晶格QCD中介子和介子的电磁形因子的手性行为。为了将晶格数据与手性微扰理论（ChPT）进行直接比较，我们采用了具有精确手性对称的重叠夸克作用。规范系综的晶格间距为0.11 fm，四个介子质量在M＿pi \simeq 290 MeV和540 MeV之间，奇异夸克质量m＿s接近其物理值。我们利用全对全夸克传播子技术高精度地计算了电磁形状因子。分别利用重加权技术和夸克场的扭曲边界条件，研究了它们对m＿s和动量传递的依赖关系。与SU(2)和SU(3) ChPT的详细比较表明，手性展开中的次-次-前阶项对于描述本工作所研究的介子质量范围内形状因子的手性行为非常重要。我们估计了相关的低能常数和电荷半径，并与现象学和实验结果相吻合。
We study the chiral behavior of the electromagnetic (EM) form factors of pion and kaon in three-flavor lattice QCD. In order to make a direct comparison of the lattice data with chiral perturbation theory (ChPT), we employ the overlap quark action that has exact chiral symmetry. Gauge ensembles are generated at a lattice spacing of 0.11 fm with four pion masses ranging between M_pi \simeq 290 MeV and 540 MeV and with a strange quark mass m_s close to its physical value. We utilize the all-to-all quark propagator technique to calculate the EM form factors with high precision. Their dependence on m_s and on the momentum transfer is studied by using the reweighting technique and the twisted boundary conditions for the quark fields, respectively. A detailed comparison with SU(2) and SU(3) ChPT reveals that the next-to-next-to-leading order terms in the chiral expansion are important to describe the chiral behavior of the form factors in the pion mass range studied in this work. We estimate the relevant low-energy constants and the charge radii, and find reasonable agreement with phenomenological and experimental results.