The quark mass gap in strong magnetic fields

TL;DR

This paper proposes a new explanation for the behavior of quark mass gaps in strong magnetic fields, addressing phenomena like inverse magnetic catalysis and linear growth of chiral condensates observed in lattice QCD data.

Contribution

It introduces a scenario where the quark mass gap remains near Lambda_QCD, contrasting with previous models predicting a gap proportional to |eB|^{1/2}.

Findings

Addresses inverse magnetic catalysis.

Explains linear growth of chiral condensate.

Proposes the quark mass gap stays near Lambda_QCD.

Abstract

Quarks in strong magnetic fields (|eB|>>Lambda_QCD^2 ~ 0.04 GeV^2) acquire enhanced infrared phase space proportional to |eB|. Accordingly they provide larger chiral condensates and stronger backreactions to the gluon dynamics. Confronting theories with lattice data at various values of |eB|, one can test theoretical ideas as well as validity of various approximations, domain of applicability of the effective models, and so on. The particularly interesting findings on the lattice are inverse magnetic catalysis and linear growth of the chiral condensate as a function of |eB|, which pose theoretical challenges. In this talk we propose a scenario to explain both phenomena, claiming that the quark mass gap should stay at around ~ Lambda_QCD, instead of ~|eB|^{1/2} which has been supposed from dimensional arguments and/or effective model calculations. The contrast between infrared and ultraviolet behaviors of the interaction is a key ingredient to obtain the mass gap of ~Lambda_QCD.