Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measurement of the generalized form factors near threshold via $\gamma^*
  p \to n\pi^+$ at high $Q^2$   We report the first extraction of the pion-nucleon multipoles near the
production threshold for the $n\pi^+$ channel at relatively high momentum
transfer ($Q^2$ up to 4.2 $\rm{GeV^2}$). The dominance of the s-wave transverse
multipole ($E_{0+}$), expected in this region, allowed us to access the
generalized form factor $G_1$ within the light-cone sum rule (LCSR) framework
as well as the axial form factor $G_A$. The data analyzed in this work were
collected by the nearly $4\pi$ CEBAF Large Acceptance Spectrometer (CLAS) using
a 5.754 $\rm{GeV}$ electron beam on a proton target. The differential cross
section and the $\pi-N$-multipole $E_{0+}/G_D$ were measured using two
different methods, the LCSR and a direct multipole fit. The results from the
two methods are found to be consistent and almost $Q^2$ independent.

24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex