自旋物理中的经典和量子约束
Classical and quantum constraints in spin physics
摘要：
来自于P、C、T和全同粒子等离散对称性对自旋观测量的约束可以分为两类：1）经典约束，保证了对称操作下截面的不变性; 2）非经典约束，只能在振幅水平上获得。同样，积极性约束也可以分为经典约束和非经典约束。前者保证了外粒子的任意单个极化的截面为正，后者将这一要求扩展到纠缠外自旋的情况。证明了经典正性域与可分性域是对偶的
英文摘要：
Constraints on spin observables coming from discrete symmetries such as P, C, T and identical particles may be divided in two types: 1) classical ones, which insure the invariance of the cross sections under the symmetry operation; 2) non-classical ones, which can only be obtained at the level of amplitudes. Similarly, positivity constraints can be divided into classical and non-classical constraints. The former insure the positivity of the cross section for arbitrary individual polarisations of the external particles, the latter extend this requirement to the case of entangled external spins. The domain of classical positivity is shown to be dual to the domain of separability
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
