High-quality composite Pati-Salam axion

We present a composite QCD axion model where the Peccei-Quinn symmetry emerges as a high-quality, accidental symmetry. The axion potential is only modified by eight-fermion, dimension-12 operators, which if present at the Planck scale, allow for axion dark matter from misalignment while solving the strong <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mi>C</a:mi> <a:mi>P</a:mi> </a:math> problem. The model is an <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"> <c:mi>SU</c:mi> <c:mo stretchy="false">(</c:mo> <c:msub> <c:mi>N</c:mi> <c:mi>c</c:mi> </c:msub> <c:mo stretchy="false">)</c:mo> </c:math> gauge theory with ten flavors where the Pati-Salam unified subgroup <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"> <g:mi>SO</g:mi> <g:mo stretchy="false">(</g:mo> <g:mn>6</g:mn> <g:mo stretchy="false">)</g:mo> <g:mo>×</g:mo> <g:mi>SO</g:mi> <g:mo stretchy="false">(</g:mo> <g:mn>4</g:mn> <g:mo stretchy="false">)</g:mo> <g:mo>⊂</g:mo> <g:mi>SU</g:mi> <g:mo stretchy="false">(</g:mo> <g:mn>10</g:mn> <g:msub> <g:mo stretchy="false">)</g:mo> <g:mi>L</g:mi> </g:msub> </g:math> and <o:math xmlns:o="http://www.w3.org/1998/Math/MathML" display="inline"> <o:mi>Sp</o:mi> <o:mo stretchy="false">(</o:mo> <o:mn>10</o:mn> <o:mo stretchy="false">)</o:mo> <o:mo>⊂</o:mo> <o:mi>SU</o:mi> <o:mo stretchy="false">(</o:mo> <o:mn>10</o:mn> <o:msub> <o:mo stretchy="false">)</o:mo> <o:mi>R</o:mi> </o:msub> </o:math> are weakly gauged. The dynamics breaks <u:math xmlns:u="http://www.w3.org/1998/Math/MathML" display="inline"> <u:mi>SU</u:mi> <u:mo stretchy="false">(</u:mo> <u:mn>10</u:mn> <u:msub> <u:mo stretchy="false">)</u:mo> <u:mi>L</u:mi> </u:msub> <u:mo>×</u:mo> <u:mi>SU</u:mi> <u:mo stretchy="false">(</u:mo> <u:mn>10</u:mn> <u:msub> <u:mo stretchy="false">)</u:mo> <u:mi>R</u:mi> </u:msub> <u:mo stretchy="false">→</u:mo> <u:mi>SU</u:mi> <u:mo stretchy="false">(</u:mo> <u:mn>10</u:mn> <u:msub> <u:mo stretchy="false">)</u:mo> <u:mi>V</u:mi> </u:msub> </u:math> and the weakly gauged groups to <db:math xmlns:db="http://www.w3.org/1998/Math/MathML" display="inline"> <db:mi mathvariant="normal">U</db:mi> <db:mo stretchy="false">(</db:mo> <db:mn>3</db:mn> <db:mo stretchy="false">)</db:mo> <db:mo>×</db:mo> <db:mi mathvariant="normal">U</db:mi> <db:mo stretchy="false">(</db:mo> <db:mn>2</db:mn> <db:mo stretchy="false">)</db:mo> <db:mo>⊃</db:mo> <db:mi>SU</db:mi> <db:mo stretchy="false">(</db:mo> <db:mn>3</db:mn> <db:msub> <db:mo stretchy="false">)</db:mo> <db:mi>c</db:mi> </db:msub> <db:mo>×</db:mo> <db:mi>SU</db:mi> <db:mo stretchy="false">(</db:mo> <db:mn>2</db:mn> <db:msub> <db:mo stretchy="false">)</db:mo> <db:mi>L</db:mi> </db:msub> <db:mo>×</db:mo> <db:mi mathvariant="normal">U</db:mi> <db:mo stretchy="false">(</db:mo> <db:mn>1</db:mn> <db:msub> <db:mo stretchy="false">)</db:mo> <db:mi>Y</db:mi> </db:msub> </db:math> , with the QCD axion identified as one of the Nambu-Goldstone bosons. This axion has a relatively large coupling to photons while a residual <sb:math xmlns:sb="http://www.w3.org/1998/Math/MathML" display="inline"> <sb:msub> <sb:mover accent="true"> <sb:mi>θ</sb:mi> <sb:mo stretchy="false">¯</sb:mo> </sb:mover> <sb:mi>eff</sb:mi> </sb:msub> </sb:math> may be just below the current limit on the neutron electric dipole moment. If the dimension-12 operators are present near the grand unified theory scale, they can cause domain wall networks to decay, allowing for axion dark matter even for the postinflationary scenario.