Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Prompt hadroproduction of C-even quarkonia in the light-front $k_T$
  -factorization approach   We present a new approach for the prompt production of quarkonia which is
based on the $k_T$-factorization method. The production of even C-parity
quarkonia proceeds via the fusion of two (off-shell) gluons. Especially in the
kinematics of the LHCb experiment these processes are thus expected to be a
sensitive probe of the small-$x$ gluon distribution. We calculate the relevant
off-shell matrix elements in terms of the light-front wave functions of the
quarkonium states. We present our results for scalar and pseudoscalar charmonia
and discuss photon transition form factors as well as cross sections for prompt
hadroproduction.
  We compare our results for the $\eta_c$ to recent LHCb data.

17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol