Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: In-medium reduction of the \eta' mass in \sqrt{s_NN} = 200 GeV Au+Au
  collisions   A reduction of the mass of the \eta'(958) meson may indicate the restoration
of the UA(1) symmetry in a hot and dense hadronic matter, corresponding to the
return of the 9th, "prodigal" Goldstone boson. We report on an analysis of a
combined PHENIX and STAR data set on the intercept parameter of the two-pion
Bose-Einstein correlation functions, as measuremed in \sqrt{s_NN} = 200 GeV
Au+Au collisions at RHIC. To describe this combined PHENIX and STAR dataset, an
in-medium \eta' mass reduction of at least 200 MeV is needed, at the 99.9 %
confidence level in a broad model class of resonance multiplicities. Energy,
system size and centrality dependence of the observed effect is also discussed.

22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org