Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Light-front representation of chiral dynamics with Delta isobar and
  large-N_c relations   Transverse densities describe the spatial distribution of electromagnetic
current in the nucleon at fixed light-front time. At peripheral distances b =
O(M_pi^{-1}) the densities are governed by chiral dynamics and can be
calculated model-independently using chiral effective field theory (EFT).
Recent work has shown that the EFT results can be represented in
first-quantized form, as overlap integrals of chiral light-front wave functions
describing the transition of the nucleon to soft-pion-nucleon intermediate
states, resulting in a quantum-mechanical picture of the peripheral transverse
densities. We now extend this representation to include intermediate states
with Delta isobars and implement relations based on the large-N_c limit of QCD.
We derive the wave function overlap formulas for the Delta contributions to the
peripheral transverse densities by way of a three-dimensional reduction of
relativistic chiral EFT expressions. Our procedure effectively maintains
rotational invariance and avoids the ambiguities with higher-spin particles in
the light-front time-ordered approach. We study the interplay of pi-N and
pi-Delta intermediate states in the quantum-mechanical picture of the densities
in a transversely polarized nucleon. We show that the correct N_c-scaling of
the charge and magnetization densities emerges as the result of the particular
combination of currents generated by intermediate states with degenerate N and
Delta. The off-shell behavior of the chiral EFT is summarized in contact terms
and can be studied easily. The methods developed here can be applied to other
peripheral densities and to moments of the nucleon's generalized parton
distributions.

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The categories of this paper are: q-alg
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The categories of this paper are: alg-geom
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The categories of this paper are: ao-sci
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The categories of this paper are: gr-qc
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The categories of this paper are: cs
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The categories of this paper are: eess
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The categories of this paper are: comp-gas
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The categories of this paper are: adap-org
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The categories of this paper are: bayes-an
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The categories of this paper are: stat
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The categories of this paper are: mtrl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: supr-con
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The categories of this paper are: dg-ga
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The categories of this paper are: plasm-ph
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The categories of this paper are: funct-an