论文标题
剪切诱导的极化：碰撞贡献
Shear induced polarization: Collisional contributions
论文作者
论文摘要
已经意识到，热剪切在重离子碰撞中颗粒的极化自旋中起着与热涡度相似的作用。我们指出，剪切具有基本差异，它导致介质中的颗粒重新分布。重新分布通过自我能源产生了对自旋极化的额外贡献，这在参数上与文献中迄今为止所考虑的阶数相同。自我能量的贡献在一般情况下取决于。我们介绍了沿Schwinger-keldysh轮廓伸展的双量规链路，以恢复量规的不变性。我们还概括了适应Schwinger-keldysh轮廓的直路。我们发现与仪表链路相关的另一个贡献，该链接在参数上也是相同的顺序。我们用剪切的无质量QED血浆中的大量探测器说明了这两个贡献。当探针费用的动量大得多时，从组合的贡献中发现了对自旋极化的适度抑制。
It has been realized that thermal shear plays a similar role as thermal vorticity in polarizing spin of particles in heavy ion collisions. We point out that shear has a fundamental difference that it leads to particle redistribution in the medium. The redistribution gives rise to an additional contribution to spin polarization through the self-energy, which is parametrically the same order as the one considered so far in the literature. The self-energy contribution is in general gauge dependent. We introduce double gauge links stretching along the Schwinger-Keldysh contour to restore gauge invariance. We also generalize the straight path to adapt to the Schwinger-Keldysh contour. We find another contribution associated with the gauge link, which is also parametrically the same order. We illustrate the two contributions with a massive probe fermion in massless QED plasma with shear. A modest suppression of spin polarization is found from the combined contributions when the probe fermion has momentum much greater than the temperature.
