Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Heavy-light mesons beyond ladder approximation   The heavy-light mesons are studied within the framework of Dyson-Schwinger
equations of QCD. Inspired by the axial-vector Ward-Takahashi identity
resulting from the chiral symmetry, we propose a truncation scheme beyond the
ladder approximation without introducing any additional parameter. For the
pseudoscalar and vector heavy-light mesons, the obtained mass spectrum has the
level of relative errors at $5\%$ compared with experimental data and
lattice-QCD results. For the leptonic decay constants, our results are
comparable with those from experiments and/or lattice QCD. For some channels,
the discrepancies are sizable but significantly smaller than those using the
equal spacing rule. The truncation scheme proposed in this work is simple and
could be improved and applied to study other open flavor hadrons including both
mesons and baryons.

21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin