Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electric dipole moment induced by a QCD instanton in an external
  magnetic field   In the chiral magnetic effect, there is a competition between a strong
magnetic field, which tends to project positively charged particles to have
spin aligned along the magnetic field, and a chirality imbalance which may be
produced locally by a topologically nontrivial gauge field such as an
instanton. We study the properties of the Euclidean Dirac equation for a light
fermion in the presence of both a constant abelian magnetic field and an SU(2)
instanton. In particular, we analyze the zero modes analytically in various
limits, both on R^4 and on the four-torus, in order to compare with recent
lattice QCD results, and study the implications for the electric dipole moment.

22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol