标题： $Δ$重子在协变规范夸克模型中的形状 显示英文标题

标题： The shape of the $Δ$ baryon in a covariant spectator quark model

摘要： 使用一种协变的杂交夸克模型，该模型描述了最近的格点QCD数据对于$\Delta$电磁形式因子以及所有可用的实验数据对于$\gamma N \to \Delta$转换，我们分析了$\Delta$重子的电荷和磁偶极分布，并讨论了它的形状。 我们得出结论，$\Delta$的四极矩是变形的良好指标，而$\Delta^+$的电荷分布具有扁平形状。 我们还计算了横向矩，发现它们不能对基本形状得出明确的结论。 显示英文摘要

摘要： Using a covariant spectator quark model that describes the recent lattice QCD data for the $\Delta$ electromagnetic form factors and all available experimental data on $\gamma N \to \Delta$ transitions, we analyze the charge and magnetic dipole distributions of the $\Delta$ baryon and discuss its shape. We conclude that the quadrupole moment of the $\Delta$ is a good indicator of the deformation and that the $\Delta^+$ charge distribution has an oblate shape. We also calculate transverse moments and find that they do not lead to unambiguous conclusions about the underlying shape.