Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: What hard probes tell us about the quark-gluon plasma: Theory   In the study of the quark-gluon plasma in high-energy heavy-ion collisions,
hard and electromagnetic (EM) processes play an essential role as probes of the
properties of the dense medium. They can be used to study a wide range of
properties of the dense medium in high-energy heavy-ion collisions, from
space-time profiles of the dense matter, bulk transport coefficients to EM
responses and the jet transport parameter. I review in this talk these medium
properties, how they can be studied through hard and EM probes and the status
of recent theoretical and phenomenological investigations.

37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
5
The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio