Speaker
Michal Krelina
(Czech Technical University in Prague, FNSPE)
Description
The $p_T$ spectrum of direct photons, measured at small $p_T$ in $AA$ collisions,
considerably exceeds the expectations, based on the NLO perturbative calculations. The latter miss the illuminating effect of parton density increase at low $x$ due to the mutual enhancement of the saturation scales in both nuclei.
This effect can be naturally implemented within the dipole formalism, which allows performing calculation even at small $p_T$, that is not reachable with perturbative calculations.
We observe a significant enhancement of the direct photon yield,
apart from the usual Cronin effect in the nuclear modification factor, $R_{AA}$.
Author
Michal Krelina
(Czech Technical University in Prague, FNSPE)
Co-author
Boris Kopeliovich
(UTFSM)
