Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Flavor separation of the Boer-Mulders function from unpolarized $\pi^-
  p$ and $\pi^- D$ Drell-Yan processes   We show that measuring the $\cos 2\phi $ angular dependence in unpolarized
Drell-Yan processes with $\pi^-$ beams colliding on proton and deuteron targets
can determine the ratio of the Boer-Mulders functions for $d$ and $u$ quarks
inside the proton $h_1^{\perp,d}/h_1^{\perp,u}$, which is still lack of
theoretical constraint. The comparison of the $\cos 2 \phi$ asymmetries
measured in unpolarized $\pi^- p$ and $\pi^- D$ Drell-Yan processes, which are
accessible at CERN by the COMPASS collaboration, can help to discriminate
whether $h_1^\perp$ effects or QCD vacuum effects are preferred by data.

26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc