Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The semileptonic decays $B_c^* \to \eta_c \ell \bar{\nu}_{\ell} $ with
  QCD sum rules   In this article, we calculate the $B_c^* \to \eta_c$ form-factors with the
three-point QCD sum rules, then study the semileptonic decays $B_c^* \to \eta_c
\ell \bar{\nu}_{\ell}$. The tiny decay widths may be observed experimentally in
the future at the LHCb, while the $B_c^* \to \eta_c$ form-factors can be taken
as basic input parameters in other phenomenological analysis.

15
The categories of this paper are: nucl-ex
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The categories of this paper are: stat
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph