@misc{10481/61476,
year = {2019},
month = {8},
url = {http://hdl.handle.net/10481/61476},
abstract = {The early-time evolution of the system generated in ultra-relativistic heavy
ion collisions is dominated by the presence of strong color  fields known as Glasma  fields.
These can be described following the classical approach embodied in the Color Glass Condensate
effective theory, which approximates QCD in the high gluon density regime. In this
framework we perform an analytical  first-principles calculation of the two-point correlator
of the divergence of the Chern-Simons current at proper time T = 0+, which characterizes
the early fluctuations of axial charge density in the plane transverse to the collision
axis. This object plays a crucial role in the description of anomalous transport phenomena
such as the Chiral Magnetic Effect. We compare our results to those obtained under
the Glasma Graph approximation, which assumes gluon field correlators to obey Gaussian
statistics. While this approach proves to be equivalent to the exact calculation in the limit
of short transverse separations, important differences arise at larger distances, where our
expression displays a remarkably slower fall-off than the Glasma Graph result (1=r4 vs.
1=r8 power-law decay). This discrepancy emerges from the non-linear dynamics mapping
the Gaussianly-distributed color source densities onto the Glasma fields, encoded in the
classical Yang-Mills equations. Our results support the conclusions reached in a previous
work, where we found indications that the color screening of correlations in the transverse
plane occurs at relatively large distances.},
organization = {Partial funding by a
FP7-PEOPLE-2013-CIG Grant of the European Commission, reference QCDense/631558,
the MINECO project FPA2016-78220 of the Spanish Government, and the `La Caixa'
Banking Foundation is gratefully acknowledged by the author.},
publisher = {Springer Nature},
keywords = {Heavy Ion Phenomenology},
title = {Topological charge fluctuations in the Glasma},
doi = {10.1007/JHEP08(2019)026},
author = {Guerrero Rodríguez, Pablo},
}