Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Azimuthal asymmetries in SIDIS di-hadron muoproduction off
  longitudinally polarized protons at COMPASS   In this review a first comprehensive study of azimuthal asymmetries in
semi-inclusive deep inelastic muoproduction of hadron pairs off longitudinally
polarized protons at COMPASS is presented. The study is based on data taken in
2007 and 2011, obtained by impinging a high-energetic $\mu^+$ beam of $160$
GeV/$\it{c}$, respectively $200$ GeV/$\it{c}$, momentum on a solid ammonia
target. The discussion is focused on both leading and subleading longitudinal
target-spin-dependent asymmetries arising in the di-hadron SIDIS cross section,
addressing the role of spin-orbit couplings and quark-gluon correlations in the
framework of collinear or transverse momentum dependent factorization.

17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc