Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The SPS Heavy Ion Programme   Statistical QCD predicts with increasing temperature a transition from
hadronic matter to a plasma of deconfined quarks and gluons. The SPS Heavy Ion
Programme was initiated to study this transition and the resulting quark-gluon
plasma. After summarizing the different probes for the collision evolution, I
survey the experimental results obtained so far and assess the conclusions that
can be drawn.

5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex