Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Effective Theories of Dark Mesons with Custodial Symmetry   Dark mesons are bosonic composites of a new, strongly-coupled sector beyond
the Standard Model. We consider several dark sectors with fermions that
transform under the electroweak group, as arise from a variety of models
including strongly-coupled theories of dark matter (e.g., stealth dark matter),
bosonic technicolor (strongly-coupled indcued electroweak symmetry breaking),
vector-like confinement, etc. We consider theories with two and four flavors
under an $SU(N)$ strong group that acquire variously chiral, vector-like, and
mixed contributions to their masses. We construct the non-linear sigma model
describing the dark pions and match the ultraviolet theory onto a low energy
effective theory that provides the leading interactions of the lightest dark
pions with the Standard Model. We uncover two distinct classes of effective
theories that are distinguishable by how the lightest dark pions decay:
"Gaugephilic": where $\pi^0 \rightarrow Z h$, $\pi^\pm \rightarrow W h$
dominate once kinematically open, and "Gaugephobic": where $\pi^0 \rightarrow
\bar{f} f$, $\pi^\pm \rightarrow \bar{f}' f$ dominate. Custodial $SU(2)$ plays
a critical role in determining the "philic" or "phobic" nature of a model. In
dark sectors that preserve custodial $SU(2)$, there is no axial anomaly, and so
the decay $\pi^0 \rightarrow \gamma\gamma$ is highly suppressed. In a companion
paper, we study dark pion production and decay at colliders, obtaining the
constraints and sensitivity at the LHC.

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The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs
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The categories of this paper are: acc-phys
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The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
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The categories of this paper are: comp-gas
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The categories of this paper are: mtrl-th
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The categories of this paper are: supr-con
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The categories of this paper are: nucl-th