Quark and Gluon Condensates in Isospin Matter

TL;DR

This paper investigates how quark and gluon condensates behave in isospin matter at low to intermediate densities, revealing a suppression of quark condensates and an unexpected enhancement of gluon condensates, with implications for lattice QCD tests.

Contribution

It provides a novel analysis of condensate behavior in isospin matter using the Hellmann-Feynman theorem and models, highlighting the universal enhancement of gluon condensates in meson Bose condensates.

Findings

Quark condensate is strongly suppressed at intermediate densities.

Gluon condensate is enhanced and can exceed vacuum values.

Results are testable via lattice calculations at finite isospin density.

Abstract

Applying the Hellmann-Feynman theorem to a charged pion gas, the quark and gluon condensates at low isospin density are determined by precise pion properties. At intermediate density around $ f_\pi^2m_\pi$, from both the estimation for the dilute pion gas and the calculation with Nambu--Jona-Lasinio model, the quark condensate is strongly and monotonously suppressed, while the gluon condensate is enhanced and can be larger than its vacuum value. This unusual behavior of the gluon condensate is universal for Bose condensed matter of mesons. Our results can be tested by lattice calculations at finite isospin density.