QCD Kondo effect: quark matter with heavy-flavor impurities

Understand

We show that the Kondo effect occurs in light quark matter which contains heavy quarks as impurities.

• We consider a scattering between a heavy-flavor impurity and a light quark near a Fermi surface which is mediated by gluon-exchange interactions.
• We find that the scattering amplitude has a logarithmic infrared divergence originating from imperfect cancellation between quark-impurity and hole-impurity scatterings in a loop integral, implying the presence of a strongly coupled regime near the Fermi surface.
• Renormalization group method is used to find the Kondo scale where a running coupling constant hits a Landau pole.