Soubhik Kumar (Berkeley)

“The High-Quality QCD Axion”

The QCD axion provides an elegant solution to the Strong CP Problem. While the minimal realization is vulnerable to the so-called “Axion Quality Problem”, I will consider a more robust realization in the presence of a mirror sector related to the Standard Model by a (softly broken) Z2 symmetry. Interestingly, the resulting “heavy” axion has a large and uncharted parameter space where it behaves as a Long-Lived Particle (LLP). By considering the defining axionic coupling to gluons, I will argue that the long-lived nature of the signal can be used to veto background, and evaluate the prospect of discovery of GeV scale axions at the HL-LHC. I will also describe the physics potential of DUNE in this context.