Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Deep Inelastic Scattering at Large Energy and Momentum Transfers: Recent
  Results from HERA   Data from H1 and ZEUS on the structure and the quark and gluon densities of
the proton are discussed. A brief excursion is made into the field of inclusive
diffraction by deep inelastic scattering. The comparison of e- p and e+ p
scattering at large momentum transfers demonstrates clearly the presence of
weak contributions in neutral current interactions. The comparison with the
corresponding charged current results shows at Q2 values above the masses
squared of the heavy vector bosons the unification of electromagnetic and weak
interactions. The new data are testing the validity of the Standard Model down
to spatial resolutions of the order of 10^{-16} cm. Intensive searches have
been performed for a manifestation of instantons, for signs of compositeness of
quarks and leptons and for the effect of extra dimensions.

7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
6
The categories of this paper are: astro-ph
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th