Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quarkonium polarization in Pb+Pb collisions in the improved color
  evaporation model   We apply our calculation of direct $J/\psi$ production in the improved color
evaporation mode at ${\mathcal O}(\alpha_s^3)$ in collinear factorization to
Pb+Pb collisions. The cold nuclear matter effects of nuclear modifications of
the parton densities and intrinsic transverse momentum broadening are included.
We find that the polarization is independent of these effects. Our calculations
are compared to the Pb+Pb polarization parameters extracted by the ALICE
Collaboration at $\sqrt{s_{NN}} = 5.02$ TeV.

26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an