Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin Orbit Correlations and the Structure of the Nucleon   Extensive experimental measurements of spin and azimuthal asymmetries in
various processes have stimulated theoretical interest and progress in studies
of the nucleon structure. Interpretation of experimental data in terms of
parton distribution functions, generalized to describe transverse momentum and
spatial parton distributions, is one of the main remaining challenges of modern
nuclear physics. These new parton distribution and fragmentation functions
encode the motion and the position of partons and are often referred to as
three-dimensional distributions describing the three-dimensional (3D) structure
of the nucleon. Understanding of the production mechanism and performing
phenomenological studies compatible with factorization theorems using minimal
model assumptions are goals of analysis of the experimental data. HERMES and
COMPASS Collaborations and experiments at Jefferson Lab have collected a wealth
of polarized and unpolarized Semi-Inclusive Deep Inelastic Scattering (SIDIS)
data. These data play a crucial role in current understanding of nucleon
spin-phenomena as they cover a broad kinematical range. The Jefferson Lab 12
GeV upgrade data on polarized and unpolarized SIDIS will have remarkably higher
precision at large parton fractional momentum $x$ compared to the existing
data. We argue that both experimental and phenomenological communities will
benefit from development of a comprehensive extraction framework that will
facilitate extraction of 3D nucleon structure, help understand various
assumptions in extraction and data analysis, help to insure the model
independence of the experimental data and validate the extracted functions. In
this review we present the latest developments in the field of the spin
asymmetries and discuss different components involved in precision extraction
of 3D partonic distribution and fragmentation functions.

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The categories of this paper are: econ
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The categories of this paper are: q-fin
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The categories of this paper are: cond-mat
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The categories of this paper are: patt-sol
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The categories of this paper are: cmp-lg
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The categories of this paper are: gr-qc
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-th
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The categories of this paper are: astro-ph
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The categories of this paper are: solv-int
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The categories of this paper are: comp-gas
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The categories of this paper are: ao-sci
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The categories of this paper are: plasm-ph
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The categories of this paper are: math
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The categories of this paper are: atom-ph
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The categories of this paper are: chem-ph