Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Higher-order corrections to exclusive production of charmonia at B
  factories   As a test of the color-singlet mechanism of the nonrelativistic QCD (NRQCD)
factorization approach, we consider the exclusive two-quarkonium productions in
electron-positron annihilation e+ e- -> eta_c + gamma and e+ e- -> J/psi +
J/psi at B factories. The cross sections are computed to the next-to-leading
order in alpha_s and are resummed to all orders in half the relative velocity v
of the charm quark in each meson rest frame. The available theoretical
prediction of the cross section for e+ e- -> J/psi + eta_c at the same level of
theoretical accuracies is consistent with the available experimental data.
Those for e+ e- -> eta_c + gamma and e+ e- -> J/psi + J/psi that are computed
new in this work can be tested against the data from future super B factories.

27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con