Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the role of magnetic field in photon excess in heavy ion collisions   Synchrotron photon spectrum in heavy-ion collisions is computed taking into
account the spatial and temporal structure of magnetic field. It is found that
a significant fraction of photon excess in heavy-ion collisions in the region
$k_\bot=1-3$GeV can be attributed to the synchrotron radiation. Azimuthal
anisotropy of the synchrotron photon spectrum is characterized by the Fourier
coefficients $v_2=4/7$ and $v_4=1/10$ that are independent of photon momentum
and centrality.

1
The categories of this paper are: cs
2
The categories of this paper are: math
9
The categories of this paper are: nlin
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ