${\eta }^{\prime }$ Production in Nucleus-Nucleus collisions as a probe of chiral dynamics

Abstract

We argue that, because of the peculiar properties of the ${\eta }^{\prime }$ meson, it is a promising probe of "chiral" dynamics. In particular, we show that a rotating gluon-dominated plasma might lead to an enhanced production of ${\eta }^{\prime }$ w.r.t. statistical model expectations. The presence of a strong topological susceptibility might give a similar effect. In both cases, unlike the statistical model,we expect a non-trivial dependence on event geometry, such as initial volume and impact parameter. Hence, an observation of ${\eta }^{\prime }/{\pi }^0$ ratio depending strongly on impact parameter might be a good indication of chiral effects, either from vorticity or topological phases of QCD

Comments: Version accepted for publication, physical review C