论文标题
NF = 2 + 1个晶格QCD的核子等分子耦合在物理点
Nucleon isovector couplings in Nf = 2 + 1 lattice QCD at the physical point
论文作者
论文摘要
我们为在物理点（$m_π= 135 $ meV）测量的核子的标量和张量等耦合（$ g_s $和$ g_t $）的结果提供了结果，单个晶格间距为$ 0.085\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\降我们的计算是通过PACS合作与非扰动$ {\ cal o}（a）$改进的Wilson Quark Action和IWASAKI对$（10.9 \ {\ rm fm}）^4 $ and $（5.5 \ flm fm fm fm fm fm fm fm fm fm fin of fin of pac的$ {\ cal o}（a）合作生成的两种量规配置的集合。在统计精度的水平上未显示核子质量小于0.5％。我们计算矢量，轴向，标量和张量通道中的核子三分相关功能。我们确认，在$（10.9 \ {\ rm fm}）^4 $的大空间体积上的核子轴向耦合的先前结果没有有限尺寸的效果，在统计精度的1.9％的水平上。对于重新归一化，我们首先使用RI/SMOM $ _ {（γ_μ）} $ ri/smom $ _ {（γ_μ）} $方案重新归一致，$ g_t $非扰动，这是Rome-Southampton RI/MOM方案的变体，具有降低的系统错误，作为中间方案。我们通过RI/SMOM $ _ {（（γ_μ）} $和$ \ overline {\ rm MS} $ schemes在扰动理论的帮助下，以及$ g_s = 0.927（71），我们通过$ \ Overline {\ rm MS} $方案在2 GEV的重新归一化量表中评估我们的最终结果。 stat}（22）_ {\ rm syst} $和$ g_t = 1.036（6）_ {\ rm stat}（20）_ {\ rm syst} $。
We present results for the scalar and tensor isovector-couplings ($g_S$ and $g_T$) of the nucleon measured at the physical point ($M_π=135$ MeV) with a single lattice spacing of $0.085\ \mathrm{fm}$ in 2+1 flavor QCD. Our calculations are carried out with two ensembles of gauge configurations generated by the PACS Collaboration with nonperturbatively ${\cal O}(a)$ improved Wilson quark action and Iwasaki gauge action on $(10.9\ {\rm fm})^4$ and $(5.5\ {\rm fm})^4$ lattices, where the finite-size effect on the nucleon mass was not shown at the level of the statistical precision less than 0.5%. We compute the nucleon three-point correlation functions in the vector, axial, scalar, and tensor channels. We confirm that our previous result of the nucleon axial coupling on the large spatial volume of $(10.9\ {\rm fm})^4$ has no finite-size effect at the level of the statistical precision of 1.9%. For the renormalization, we first renormalize $g_S$ and $g_T$ nonperturbatively using the RI/SMOM$_{(γ_μ)}$ scheme, a variant of Rome-Southampton RI/MOM scheme with reduced systematic errors, as the intermediate scheme. We evaluate our final results at the renormalization scale of 2 GeV in the $\overline{\rm MS}$ scheme through matching procedure between the RI/SMOM$_{(γ_μ)}$ and $\overline{\rm MS}$ schemes with the help of perturbation theory, and then obtain $g_S=0.927(71)_{\rm stat}(22)_{\rm syst}$ and $g_T=1.036(6)_{\rm stat}(20)_{\rm syst}$.
