QED是否还有新参数?

Is There a New Parameter in QED

量子电动力学(QED)可以允许宇称破坏的费米子质量项,并由此引进一个新参量。这时不存在守恒的空间反演算符,并有明显的宇称破坏效应-电偶极矩。在手征变换下,在纯规范部分出现宇称破坏项。这一项不是对时间的全微商,所以对规范场的运动方程有贡献。用一个双联(dual)转动可以把手征转动前后的电磁场联系起来。第二类电磁场方程变成非齐次,并破坏宇称守恒。

The Fermion mass with a parity violating part in quantum electrodynamics (QED) is allowed in principle and hence introduces a new parameter. Explicit parity violating effect, the electric dipole moment is shown. A chiral rotation may turn the mass into real, however, produces a parity violating term in the pure gauge part. The latter is not the total derivative with espect to time and indeed appears in the equations of motion. The second set of Maxwell equation becomes inhamogineous, which violates parity.