High order cumulants of the azimuthal anisotropy in the dilute-dense   limit: Connected graphs
  We analytically compute higher order cumulants of the azimuthal anisotropy, $c_2\{2m\}$, and corresponding $v_2\{2m\}$ at high transverse momentum in the dilute-dense limit. The dense target is considered in the framework of the McLerran-Venugopolan model. The absolute values of the harmonics $v_2\{2m\}$ of the azimuthal anisotropy are approximately equal, $|v_2\{2m\}| \approx |v_2\{2m'\}| $, for large $m$ and $m'$. However, the harmonics with order $2m=4n$ are complex. We argue that this is a generic property of connected graphs, which remains true in the dense-dense limit. 
Vladimir Skokov
hep-ph nucl-th