Gamberg L, Goldstein G R
Department of Physics and Astronomy, University of Pennsylvania, David Rittenhouse Labs, 209 South 33rd Street, Philadelphia, Pennsylvania 19104, USA.
Phys Rev Lett. 2001 Dec 10;87(24):242001. doi: 10.1103/PhysRevLett.87.242001. Epub 2001 Nov 19.
The axial vector and tensor charge, defined as the first moments of the forward nucleon matrix elements of corresponding quark currents, are essential for characterizing the spin structure of the nucleon. There are no definitive theoretical predictions for the tensor charge, aside from several model-dependent calculations. We present a new approach that exploits the approximate mass degeneracy of the light axial vector mesons [ a1(1260), b1(1235), and h1(1170)] and uses pole dominance to calculate the tensor charge. The result is simple in form. It depends on the decay constants of the axial vector mesons and their couplings to the nucleons.
轴矢量和张量荷被定义为相应夸克流的前向核子矩阵元的一阶矩，对于刻画核子的自旋结构至关重要。除了一些依赖模型的计算外，对于张量荷尚无明确的理论预测。我们提出一种新方法，该方法利用轻轴矢量介子[a1(1260)、b1(1235)和h1(1170)]的近似质量简并性，并使用极点支配来计算张量荷。结果形式简单。它取决于轴矢量介子的衰变常数及其与核子的耦合。
