Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The heavy mesons in Nambu--Jona-Lasinio model   We propose an extended Nambu--Jona-Lasinio model to include the heavy mesons
with the heavy quark symmetry. The quark current-current interaction is
generalized to include the heavy quark currents. In order to comply with the
heavy quark spin symmetry at the heavy quark limit, the quark mass dependence
of the interaction strength is introduced. The light and heavy pseudo-scalar
and vector meson, their masses and the weak decay constants, are calculated in
the unified frame.

17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph