Stability of magnetic condensation and mass generation for confinement in SU(2) Yang-Mills theory

Abstract

In the framework of the functional renormalization group, we reexamine the stability of the Yang-Mills vacuum with a chromomagnetic condensation. We show that the Nielsen-Olesen instability of the Savvidy vacuum with a homogeneous chromomagnetic condensation disappears in the $SU(2)$ Yang-Mills theory. As a physical mechanism for maintaining the stability even for the small infrared cutoff, we argue that dynamical gluon mass generation occurs due to a BRST-invariant vacuum condensate of mass dimension-two, which is related to two-gluon bound states identified with glueballs. These results support the dual superconductor picture for quark confinement.

Comments: 12 pages, no figures; Talk given at the QCD-TNT-III-From quarks and gluons to hadronic matter: A bridge too far? 2-6 September, 2013, European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*), Villazzano, Trento (Italy)