1211.1166 (Marton Vargyas et al.)

Effects of chain decays, radial flow and $U_{A}(1)$ restoration on the
low-mass dilepton enhancement in $\s_{NN}=200$ GeV Au+Au reactions    [PDF]

Marton Vargyas, Robert Vertesi, Tamas Csorgo

In $s_{NN}$ = 200 GeV Au+Au collisions PHENIX reported a significant enhancement in the low-mass region ($0.1 < m_{ee} < 0.7$ GeV) of the dielectron spectrum, which is still not fully understood. Several theoretical works and an indirect measurement suggest that, due to the possible restoration of the $U_A(1)$ part of the chiral symmetry in a hot and dense medium, the mass of the eta' meson may substantially decrease. This work reports on a statistically acceptable description of the PHENIX low-mass dilepton enhancement using a radial flow dominated meson spectra, chain decays of long-lived resonances and an in-medium eta' mass modification.

View original: http://arxiv.org/abs/1211.1166