In this paper, we calculate the helicity rotation angle induced by Lorentz boosts. This is relevant for the study of Lorentz boost effects on quantum entanglement encoded in pairs of massive fermions, which are described in terms of positive energy solutions of the Dirac equation with definite helicity. A Lorentz boost describing the change to an inertial frame moving at uniform speed will in general rotate the particle’s helicity. We obtain the coefficients of the helicity superposition in the boosted frame and specialize our results for a perpendicular boost geometry. We verify that the helicity rotation angle can be obtained in terms of the Wigner rotation angle for spin [Formula: see text] states, bridging the framework considered in our previous works to the one of the Wigner rotations. Finally, we calculate the boost-induced spin-parity entanglement for a single particle.

中文翻译：

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洛伦兹增强引起的螺旋度旋转

在本文中，我们计算了由 Lorentz boosts 引起的螺旋度旋转角。这与洛伦兹增强效应对大质量费米子对编码的量子纠缠的研究有关，这些费米子用具有确定螺旋度的狄拉克方程的正能量解来描述。描述改变以匀速运动的惯性系的洛伦兹助推通常会旋转粒子的螺旋度。我们获得了增强框架中的螺旋叠加系数，并将我们的结果专门用于垂直增强几何。我们验证可以根据自旋 [公式：见文本] 状态的 Wigner 旋转角获得螺旋度旋转角，将我们之前工作中考虑的框架与 Wigner 旋转之一桥接。最后，