Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Global fitting of single spin asymmetry: an attempt   We present an attempt of global analysis of Semi-Inclusive Deep Inelastic
Scattering (SIDIS) $\ell p^\uparrow \to \ell' \pi X$ data on single spin
asymmetries and data on left-right asymmetry $A_N$ in $p^\uparrow p \to \pi X$
in order to simultaneously extract information on Sivers function and
twist-three quark-gluon Efremov-Teryaev-Qiu-Sterman (ETQS) function. We explore
different possibilities such as node of Sivers function in $x$ or $k_\perp$ in
order to explain "sign mismatch" between these functions. We show that
$\pi^\pm$ SIDIS data and $\pi^0$ STAR data can be well described in a combined
TMD and twist-3 fit, however $\pi^\pm$ BRAHMS data are not described in a
satisfactory way. This leaves open a question to the solution of the "sign
mismatch". Possible explanations are then discussed.

10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg