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arXiv · hep-th/9602027

Discussing the U(1)-Problem of QED_2 without Instantons

Christof Gattringer
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Abstract

We construct QED_2 with mass and flavor and an extra Thirring term. The vacuum expectation values are carefully decomposed into clustering states using the U(1)-axial symmetry of the considered operators and a limiting procedure. The properties of the emerging expectation functional are compared to the proposed theta-vacuum of QCD. The massive theory is bosonized to a generalized Sine-Gordon model (GSG). The structure of the vacuum of QED_2 manifests itself in symmetry properties of the GSG. We study the U(1)-problem and derive a Witten-Veneziano-type formula for the masses of the pseudoscalars determined from a semiclassical approximation.

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Christof Gattringer. 1996-02-06. Discussing the U(1)-Problem of QED_2 without Instantons. https://doi.org/10.1006/aphy.1996.0098

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