论文标题
$δ$共振的电磁和重力形式在协变量的夸克 - diquark方法中
Electromagnetic and gravitational form factors of $Δ$ resonance in a covariant quark-diquark approach
论文作者
论文摘要
在这项工作中，借助相对论的协变量夸克 - diquark方法，同时计算出旋转$ 3/2 $粒子的电磁和重力形式。从电磁电流的矩阵元件和系统的能量量张量的基质元件中分别提取两种形式。我们的数值结果表明，与晶格计算相比，该方法可以很好地再现电磁单极，偶极子，四极杆和八极形构型。我们获得的电磁力矩也与其他一些方法相媲美。此外，还显示了$δ$ isobar的重力形式，从而赋予系统的机械性能，例如质量和自旋分布。此外，特别给出了有关符号和D-期解释的一些讨论。
In this work, the electromagnetic and gravitational form factors of a spin-$3/2$ particle, $Δ$ resonance, are simultaneously calculated with the help of a relativistic covariant quark-diquark approach. The two kinds of form factors are separately extracted from the matrix elements of the electromagnetic current and of the energy-momentum tensor of the system. Our numerical results show that the approach can well reproduce the electromagnetic monopole, dipole, quadrupole, and octupole form factors comparing to the Lattice calculations. Our obtained electromagnetic moments are also comparable with some other approaches. Moreover, the obtained gravitational form factors, which give the mechanical properties of the system like the mass and spin distributions, are also displayed for the $Δ$ isobar. In addition, some discussions of the sign and the interpretation of the D-term are particularly given.
