Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Chiral pions in a magnetic background   We investigate the modification of the pion self-energy at finite temperature
due to its interaction with a low-density, isospin-symmetric nuclear medium
embedded in a constant magnetic background. To one loop, for fixed temperature
and density, we find that the pion effective mass increases with the magnetic
field. For the $\pi^{-}$, interestingly, this happens solely due to the trivial
Landau quantization shift $\sim |eB|$, since the real part of the self-energy
is negative in this case. In a scenario in which other charged particle species
are present and undergo an analogous trivial shift, the relevant behavior of
the effective mass might be determined essentially by the real part of the
self-energy. In this case, we find that the pion mass decreases by $\sim 10%$
for a magnetic field $|eB|\sim m_\pi^2$, which favors pion condensation at high
density and low temperatures.

31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
29
The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph