Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Angular Momentum and g_1^p Sum Rules for the Proton   The gauge invariant operator formulation of the angular momentum sum rule
${1\over2} = J_q + J_g$ for the proton is presented and contrasted with the sum
rule for the first moment of the polarised structure function $g_1^p$. The
decoupling of the axial charge $a^0$ from the angular momentum sum rule is
highlighted and the possible QCD field-theoretic basis for an angular momentum
sum rule of the form ${1\over2} = {1\over2}\D q + \D g + L_q + L_g$ is
critically discussed.

22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom