Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A review of quarkonia under strong magnetic fields   We review the properties of quarkonia under strong magnetic fields. The main
phenomena are (i) mixing between different spin eigenstates, (ii) quark Landau
levels and deformation of wave function, (iii) modification of $\bar{Q}Q$
potential, and (iv) the motional Stark effect. For theoretical approaches, we
review (i) constituent quark models, (ii) effective Lagrangians, (iii) QCD sum
rules, and (iv) holographic approaches.

35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
7
The categories of this paper are: hep-th
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math