Nucleon Charges and Electromagnetic Form Factors from 2+1+1-Flavor Lattice QCD
Nucleon Charges and Electromagnetic Form Factors from 2+1+1-Flavor Lattice QCD
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DOI：
10.1103/physrevd.89.094502
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发表时间：
2013-06
影响因子：
5
通讯作者：
Tanmoy Bhattacharya;S. Cohen;Rajan Gupta;Anosh Joseph;Huey-Wen Lin;B. Yoon
中科院分区：
文献类型：
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作者：
Tanmoy Bhattacharya;S. Cohen;Rajan Gupta;Anosh Joseph;Huey-Wen Lin;B. Yoon
我们提出了格子QCD结果的核子等矢量轴向，标量和张量的费用，等矢量电磁狄拉克和泡利形状因子，和连接部分的等oscillator费用。计算已完成使用两个合奏的HISQ晶格产生的MILC合作与2+1+1动力学口味在晶格间距为0.12 fm和轻夸克质量对应的介子与质量310和220兆电子伏。我们进行了系统的研究，包括激发态的自由度和检查的依赖性提取的核子矩阵元素的源-汇分离。这项研究表明，高统计数据，包括激发态的贡献，并在多个分离产生的数据是必要的，以消除污染，否则会导致系统误差。我们还确定了RI-south方案中的关联夸克双线性算子的重整化常数，并将我们的重整化结果与以前的动力学晶格计算进行了比较。
We present lattice-QCD results on the nucleon isovector axial, scalar and tensor charges, the isovector electromagnetic Dirac and Pauli form factors, and the connected parts of the isoscalar charges. The calculations have been done using two ensembles of HISQ lattices generated by the MILC Collaboration with 2+1+1 dynamical flavors at a lattice spacing of 0.12 fm and with light-quark masses corresponding to pions with masses 310 and 220 MeV. We perform a systematic study including excited-state degrees of freedom and examine the dependence of the extracted nucleon matrix elements on source-sink separation. This study demonstrates with high-statistics data that including excited-state contributions and generating data at multiple separations is necessary to remove contamination that would otherwise lead to systematic error. We also determine the renormalization constants of the associated quark bilinear operators in the RI-sMOM scheme and make comparisons of our renormalized results with previous dynamical-lattice calculations.