en.wikipedia.org/wiki/Left-right_model Left?right symmetry is a general principle in physics which holds that valid physical laws must not produce a different result for a motion that is left-handed than motion that is right-handed. The most common application is expressed as equal treatment of clockwise and counter-clockwise rotations from a fixed frame of reference.
The general principle is often referred to by the name chiral symmetry. The rule is absolutely valid in the classical mechanics of Newton and Einstein, but results from quantum mechanical experiments show a difference in the behavior of left-chiral versus right-chiral subatomic particles.
Particle PhysicsIn theoretical physics, the electroweak model breaks parity maximally. All its fermions are chiral Weyl fermions, which means that the weak gauge bosons only couple to left-handed quarks and leptons. Some theorists found this objectionable, and so proposed a GUT extension of the weak force which has new, high energy W' and Z' bosons which couple with right handed quarks and leptons. （この後が面白いが、数学記号が複雑なので省略する）
