Doing Spin Physics with Unpolarized Particles.
Doing Spin Physics with Unpolarized Particles.
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DOI：
10.1103/physrevlett.124.192001
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发表时间：
2019-11
影响因子：
8.6
通讯作者：
I. Ivanov;N. Korchagin;A. Pimikov;Pengming Zhang
中科院分区：
文献类型：
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作者：
I. Ivanov;N. Korchagin;A. Pimikov;Pengming Zhang
扭曲或涡旋粒子是指具有螺旋波阵面的自由传播非平面波状态。在这种状态下，粒子相对于其平均传播方向具有非零的轨道角动量。扭曲的光子和电子已经在实验中得到证实，并且可以预期在扭曲状态下产生其他粒子。如果引入碰撞，扭曲态为粒子物理学提供了一个新的自由度，现在是时候分析可能会出现什么新的见解了。在这里，我们从理论上研究了扭曲光子碰撞和扭曲e^{+}e^{-}湮灭中的共振产生，并表明这些过程作为一种全新的探测器出现在非极化初始粒子的完全包含截面中的自旋和宇称敏感的观测值。这是可能的，因为具有非零角动量的初始状态明确地打破了左右对称性，即使在螺旋度上平均时也是如此。特别地，我们展示了如何在非极化扭曲e^{+}e^{-}湮灭中产生几乎100%极化的矢量介子，以及如何控制其极化状态。
Twisted, or vortex, particles refer to freely propagating non-plane-wave states with helicoidal wave fronts. In this state, the particle possesses a nonzero orbital angular momentum with respect to its average propagation direction. Twisted photons and electrons have been experimentally demonstrated, and creation of other particles in twisted states can be anticipated. If brought in collisions, twisted states offer a new degree of freedom to particle physics, and it is timely to analyze what new insights may follow. Here, we theoretically investigate resonance production in twisted photon collisions and twisted e^{+}e^{-} annihilation and show that these processes emerge as a completely novel probe of spin and parity-sensitive observables in fully inclusive cross sections with unpolarized initial particles. This is possible because the initial state with a nonzero angular momentum explicitly breaks the left-right symmetry even when averaging over helicities. In particular, we show how one can produce almost 100% polarized vector mesons in unpolarized twisted e^{+}e^{-} annihilation and how to control its polarization state.