Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Factorization for Azimuthal Asymmetries in SIDIS at Next-to-Leading
  Power   Differential measurements of the semi-inclusive deep inelastic scattering
(SIDIS) process with polarized beams provide important information on the
three-dimensional structure of hadrons. Among the various observables are
azimuthal asymmetries that start at subleading power, and which give access to
novel transverse momentum dependent distributions (TMDs). Theoretical
predictions for these distributions are currently based on the parton model
rather than a rigorous factorization based analysis. Working under the
assumption that leading power Glauber interactions do not spoil factorization
at this order, we use the Soft Collinear Effective Theory to derive a complete
factorization formula for power suppressed hard scattering effects in SIDIS.
This yields generalized definitions of the TMDs that depend on two longitudinal
momentum fractions (one of them only relevant beyond tree level), and a
complete proof that only the same leading power soft function appears and can
be absorbed into the TMD distributions at this order. We also show that
perturbative corrections can be accounted for with only one new hard
coefficient. Factorization formulae are given for all spin dependent structure
functions which start at next-to-leading power. Prospects for improved
subleading power predictions that include resummation are discussed.

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The categories of this paper are: hep-lat
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The categories of this paper are: ao-sci
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The categories of this paper are: dg-ga
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The categories of this paper are: patt-sol
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The categories of this paper are: plasm-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-fin
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The categories of this paper are: math-ph
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The categories of this paper are: supr-con
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The categories of this paper are: econ
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: astro-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: acc-phys
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The categories of this paper are: stat