论文标题
$ {}^3 \ text {He} $的Parton分布功能上的晶格QCD约束
Lattice QCD constraints on the parton distribution functions of ${}^3\text{He}$
论文作者
论文摘要
$ {}^3 \ text {he} $的纵向动量的比例是$ u $和$ u $和$ d $ quarks的组合，首次使用lattice qcd确定。发现这种组合与组成核中的比率与Quark质量的计算相当于$M_π\ sim 800 $ MEV的计算，与统一水平的统一相一致，该计算被推断到物理夸克质量上。该约束与来自全球核部分分布函数的确定相比，这一约束与拟合的确定相比，并且要精确得多。包括NNPDF全球拟合框架中动量分数的晶格QCD确定，导致ISOVECTOR动量分数降低的不确定性降低了2.5倍，从而可以更精确地提取$ u $和$ u $和$ d $ parton分布$ {}^3 \ fext $ {}^3 \ text $。
The fraction of the longitudinal momentum of ${}^3\text{He}$ that is carried by the isovector combination of $u$ and $d$ quarks is determined using lattice QCD for the first time. The ratio of this combination to that in the constituent nucleons is found to be consistent with unity at the few-percent level from calculations with quark masses corresponding to $m_π\sim 800$ MeV, extrapolated to the physical quark masses. This constraint is consistent with, and significantly more precise than, determinations from global nuclear parton distribution function fits. Including the lattice QCD determination of the momentum fraction in the nNNPDF global fitting framework results in the uncertainty on the isovector momentum fraction ratio being reduced by a factor of 2.5, and thereby enables a more precise extraction of the $u$ and $d$ parton distributions in ${}^3\text{He}$.
