Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unified Description of Polarized and Unpolarized Quark Distributions in
  the Proton   We propose a unified new approach to describe polarized and unpolarized quark
distributions in the proton based on the gauge-gravity correspondence,
light-front holography, and the generalized Veneziano model. We find that the
spin-dependent quark distributions are uniquely determined in terms of the
unpolarized distributions by chirality separation without the introduction of
additional free parameters. The predictions are consistent with existing
experimental data and agree with perturbative QCD constraints at large
longitudinal momentum $x$. In particular, we predict the sign reversal of the
polarized down-quark distribution in the proton at $x=0.8\pm0.03$, a key
property of nucleon substructure which will be tested very soon in upcoming
experiments.

1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph