论文标题
$m_π= 200〜 {\ rm mev} $从晶状体QCD中的弹性核能散射
Elastic nucleon-pion scattering at $m_π = 200~{\rm MeV}$ from lattice QCD
论文作者
论文摘要
使用$ n _ {\ rm f} = 2+1 $动力学夸克风味和$m_π= 200〜〜 {\ rm mev} $的单个仪表场配置和$ n _ {\ rm mev} $进行弹性核能散射振幅计算。 $ s $ - 波散射长度，均具有总isospins $ i = 1/2 $和$ i = 3/2 $的$ i = 3/2 $，是从无弹性阈值以下的有限量频谱以及$ i = 3/2 $ $ p $ -wave包含$Δ（1232）$ resonance的。幅度由有效范围扩展很好地描述，其参数被限制在有限体积的能量水平上，从而确定$ i = 3/2 $散射长度，统计误差低于$ 5 \％$，而$ i = 1/2 $的统计误差要少一些。由于激发态引起的系统错误和高度部分波的影响受到控制，为将来的计算提供了途径，直到有多个晶格间距和物理体积的物理光夸克质量。
Elastic nucleon-pion scattering amplitudes are computed using lattice QCD on a single ensemble of gauge field configurations with $N_{\rm f} = 2+1$ dynamical quark flavors and $m_π = 200~{\rm MeV}$. The $s$-wave scattering lengths with both total isospins $I=1/2$ and $I=3/2$ are inferred from the finite-volume spectrum below the inelastic threshold together with the $I=3/2$ $p$-wave containing the $Δ(1232)$ resonance. The amplitudes are well-described by the effective range expansion with parameters constrained by fits to the finite-volume energy levels enabling a determination of the $I=3/2$ scattering length with statistical errors below $5\%$, while the $I = 1/2$ is somewhat less precise. Systematic errors due to excited states and the influence of higher partial waves are controlled, providing a pathway for future computations down to the physical light quark masses with multiple lattice spacings and physical volumes.
