Anisotropic fluctuations of angular momentum of heavy quarks in the Glasma

We study the evolution of the angular momentum of the heavy quarks in thevery early stage of high energy nuclear collisions, in which the background ismade of evolving Glasma fields. Given the novelty of the problem, we limitourselves to the use of toy heavy quarks with a large, unphysical mass, inorder to implement the kinetic equations for the angular momentum in thenon-relativistic limit. We find that as a consequence of the anisotropy of thebackground fields, angular momentum fluctuations are also anisotropic: weunderstand this in simple terms relating the fluctuations of the angularmomentum, $L$, to those of linear momentum. While orbital angular momentumdiffuses and develops substantial fluctuations and anisotropies, the spin doesnot. Hence, we can identify the fluctuations of $L$ with those of the totalangular momentum $J=L + S$. Therefore, our study suggests that the totalangular momentum of the heavy quarks in the early stage of high energy nuclearcollisions will present anisotropic fluctuations.