Dilepton Production from Moaton Quasiparticles

The phase diagram of QCD probably exhibits a moat regime over a large region of temperature T and chemical potential μ≠0. A moat regime is characterized by quasiparticle moatons (pions) whose energy is minimal at nonzero spatial momentum. At μ≠0, higher mass dimension operators play a critical role in a moat regime. At dimension six, there are nine possible gauge-invariant couplings between scalars and photons. For back-to-back dilepton production, only one operator contributes, which significantly enhances production near a moat threshold. This enhancement is an experimental signature of moatons.