论文标题
大动量转移时核子轴向形状因子
Nucleon axial form factor at large momentum transfers
论文作者
论文摘要
使用Poincaré-covariant Quark+Diquark Faddeev方程和相关的对称性弱的弱相互作用电流，我们在域上提供了无参数的预测，$ g_a（q^2）$，在域上$ 0 \ leq $ 0 \ leq leq x = q^2/m_n^2/m_n^2/m_n^2 \ leq leq leq leq 10 $ s $ m_n $m__。我们还提供了质子$ g_a $的风味分离的详细分析，以分成价$ u $和$ d $ quarks的贡献；并且在如此大的$ q^2 $域上可用的形式因素，可以预测风味分离的轴向电荷轻横向横向空间密度曲线。我们计算出的轴向电荷比$ g_a^d/g_a^u = -0.32（2）$与可用的实验数据一致，并且比非贵族夸克模型的典型值大。该比率的值对庞加尔式核定核能波函数中轴向矢量diquark相关性的强度敏感。使用逼真的轴向向量diquark内容，$ d $和$ u $ QUARK横向密度配置文件相似。这些预测中的一些可能有可能通过质子以$ q^2 $的质子阈值触发电源量的新数据进行测试。
Using a Poincaré-covariant quark+diquark Faddeev equation and related symmetry-preserving weak interaction current, we deliver parameter-free predictions for the nucleon axialvector form factor, $G_A(Q^2)$, on the domain $0\leq x=Q^2/m_N^2\leq 10$, where $m_N$ is the nucleon mass. We also provide a detailed analysis of the flavour separation of the proton $G_A$ into contributions from valence $u$ and $d$ quarks; and with form factors available on such a large $Q^2$ domain, predictions for the flavour-separated axial-charge light-front transverse spatial density profiles. Our calculated axial charge ratio $g_A^d/g_A^u=-0.32(2)$ is consistent with available experimental data and markedly larger in magnitude than the value typical of nonrelativistic quark models. The value of this ratio is sensitive to the strength of axialvector diquark correlations in the Poincaré-covariant nucleon wave function. Working with a realistic axialvector diquark content, the $d$ and $u$ quark transverse density profiles are similar. Some of these predictions could potentially be tested with new data on threshold pion electroproduction from the proton at large $Q^2$.
