Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The ${\Upsilon}(nS)$ ${\to}$ $B_{c}D_{s}$, $B_{c}D_{d}$ decays with
  perturbative QCD approach   The ${\Upsilon}(nS)$ ${\to}$ $B_{c}D_{s}$, $B_{c}D_{d}$ weak decays are
studied with the pQCD approach firstly. It is found that branching ratios
${\cal B}r({\Upsilon}(nS){\to}B_{c}D_{s})$ ${\sim}$ ${\cal O}(10^{-10})$ and
${\cal B}r({\Upsilon}(nS){\to}B_{c}D_{d})$ ${\sim}$ ${\cal O}(10^{-11})$, which
might be measurable in the future experiments.

7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio