论文标题
to $ n $至$nπ$矩阵元素来自晶格QCD
Toward $N$ to $Nπ$ matrix elements from lattice QCD
论文作者
论文摘要
在准弹性方案中长期基线振荡实验中检测到的中微子能量的蒙特卡洛重建需要轴向和矢量电流的QCD矩阵元件。确定轴向矩阵元素的最清洁方法是晶格QCD。但是，从相应的相关函数中提取这些函数的贡献非常复杂，这与从核子到核子 - 抑制对的过渡有关。在这项使用Pion质量$M_π= 429〜 \ Mathrm {Mev} $的试点研究中，我们首次证明可以通过将这些贡献包括在于用于创建核子的五个（反）夸克运算符中的插入器。需要相同的技术来计算与谐振产生状态相关的核子和核子散射状态之间的过渡矩阵元件。
QCD matrix elements of axial and vector currents between nucleons are required for the Monte Carlo reconstruction of the energy of neutrinos that are detected in long baseline oscillation experiments in the quasi-elastic regime. The cleanest approach for determining the axial matrix elements is lattice QCD. However, the extraction of these from the corresponding correlation functions is complicated by very large excited state contributions, that are related to transitions from the nucleon to a nucleon-pion pair. In this pilot study with a pion mass $m_π= 429~ \mathrm{MeV}$, we demonstrate for the first time that these contributions can be removed by including five-(anti)quark operators into the basis of interpolators used to create the nucleon. The same techniques will be needed to compute transition matrix elements between the nucleon and nucleon-pion scattering states that are relevant in the resonance production regime.
