QCD Kondo effect: quark matter with heavy-flavor impurities

TL;DR

This paper demonstrates the occurrence of the Kondo effect in light quark matter with heavy-flavor impurities, revealing a strongly coupled regime near the Fermi surface through gluon-mediated scattering analysis.

Contribution

It introduces the presence of the QCD Kondo effect in quark matter with heavy quark impurities and analyzes the associated infrared divergence and Kondo scale using renormalization group methods.

Findings

Logarithmic infrared divergence in scattering amplitude

Identification of a Kondo scale where coupling diverges

Analysis of gluon-exchange interactions in high density QCD

Abstract

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. Following an illustration by a simple contact-interaction model, we examine gluon-exchange interactions on the basis of high density QCD.