Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonperturbative region of effective strong coupling   In the framework of Poincar\'{e} covariant quark model the behavior of
running coupling constant $\alpha_{s}\left(Q^{2}\right)$ is considered in $Q <
1 \mbox{GeV}$ region. An analysis was carried out for pseudoscalar and vector
mesons with lepton decay constants, masses (obtained from model dependent) and
nucleon spin rules required to match their experimental counterparts. Possible
behavior of $\alpha_{s}$ with
$\alpha_{\mathrm{crit.}}=\alpha_{s}\left(Q^{2}=0\right) \sim 0.65-0.72$ in the
case of a frozen regime, which follows from experimental values of lepton decay
constant, masses and nucleon spin rules are discussed.

26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs
3
The categories of this paper are: physics
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th