Gauge invariance of a critical number of flavours in QED3.

Journal Article · Thu Jan 01 04:00:00 EST 2009 · Few-Body Syst.

OSTI ID:973776

Roberts, C D; Bashir, A; Raya, A; Sanchez-Madrigal, S

The fermion propagator in an arbitrary covariant gauge can be obtained from the Landau gauge result via a Landau-Khalatnikov-Fradkin transformation. This transformation can be written in a practically useful form in both configuration and momentum space. It is therefore possible to anticipate effects of a gauge transformation on the propagator's analytic properties. These facts enable one to establish that if a critical number of flavours for chiral symmetry restoration and deconfinement exists in noncompact QED3, then its value is independent of the gauge parameter. This is explicated using simple forms for the fermion-photon vertex and the photon vacuum polarisation. The illustration highlights pitfalls that must be avoided in order to arrive at valid conclusions. Landau gauge is seen to be the covariant gauge in which the propagator avoids modification by a non-dynamical gauge-dependent exponential factor, whose presence can obscure truly observable features of the theory.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: SC; CIC and CONA-Cy T grants
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 973776
• Report Number(s): ANL/PHY/JA-64298
• Journal Information: Few-Body Syst., Journal Name: Few-Body Syst. Journal Issue: 4 ; 2009 Vol. 46; ISSN 0177-7963; ISSN FBSYEQ
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CHIRAL SYMMETRY
CONFIGURATION
FERMIONS
GAUGE INVARIANCE
MODIFICATIONS
PHOTONS
PROPAGATOR
TRANSFORMATIONS