Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Friedberg-Lee model at finite temperature and density   The Friedberg-Lee model is studied at finite temperature and density. By
using the finite temperature field theory, the effective potential of the
Friedberg-Lee model and the bag constant $B(T)$ and $B(T,\mu)$ have been
calculated at different temperatures and densities. It is shown that there is a
critical temperature $T_{C}\simeq 106.6 \mathrm{MeV}$ when $\mu=0 \mathrm{MeV}$
and a critical chemical potential $\mu \simeq 223.1 \mathrm{MeV}$ for fixing
the temperature at $T=50 \mathrm{MeV}$. We also calculate the soliton solutions
of the Friedberg-Lee model at finite temperature and density. It turns out that
when $T\leq T_{C}$ (or $\mu \leq \mu_C$), there is a bag constant $B(T)$ (or
$B(T,\mu)$) and the soliton solutions are stable. However, when $T>T_{C}$ (or
$\mu>\mu_C$) the bag constant $B(T)=0 \mathrm{MeV}$ (or $B(T,\mu)=0
\mathrm{MeV}$) and there is no soliton solution anymore, therefore, the
confinement of quarks disappears quickly.

34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom