Instanton-induced crossover in dense QCD

We study the properties of an instanton ensemble in three-flavor dense QCD which can be regarded as an instanton plasma weakly interacting by exchanging the η′ mesons. Based on this description, we explore the chiral phase transition induced by the instanton ensemble at high baryon density in analogy with the Berezinskii-Kosterlitz-Thouless transition. Using the renormalization group approach, we show that the instanton ensemble always behaves as a screened and unpaired plasma. We also demonstrate that the chiral condensate in dense QCD is proportional to the instanton density.