The University of Queensland
Department of Mathematics
Mathematical Physics Seminar
Stability of the Monopole Condensate in SU(2) QCD, and ongoing efforts to quantise the (chromo) magnetic monopole.
Dr. Michael Walker
2.00 p.m., Wednesday December 12, 2001
Room 641, Priestly Building
Proof of confinement is a long-standing problem in Quantum ChromoDynamics (QCD). One suggested mechanism is that the QCD vacuum is a condensate of chromomagnetic monopoles which confine the chromoelectric flux via the dual Meissner effect. Essential to this hypothesis is the stability of such a vacuum, and this has been the subject of some controversy. However, the apparent instability is an artifact of using an inappropriate renormalisation scheme. Renormalising in such a way as to ensure that causality is respected removes the instability. Furthermore, by using the Cho decomposition, whose primary function is to specify the colour direction in non-Abelian gauge theories, it can be shown that the magnetic background is composed of monopoles, whereas in earlier works the origin of the background could not be specified. Importantly, an electric background is unstable and this is indicated in the one-loop effective action by a an imaginary part which vanishes when and only when the electric background vanishes. The imaginary part of the effective action is proportional to $g^2$, allowing it to be verified by a perturbative calculation. While the above treats the monopole field as a classical background field, we shall conclude with a description of our ongoing attempts to quantise it.
All interested are invited to attend.
Enquires to Yao-Zhong Zhang on 3365 2309 or yzz@maths.uq.edu.au