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arXiv · hep-th/9412018

Gauge Theories in a Bag

A. Wipf·S. Duerr
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Abstract

We investigate multi-flavour gauge theories confined in $d\es 2n$-dimensional Euclidean bags. The boundary conditions for the 'quarks' break the axial flavour symmetry and depend on a parameter $θ$. We determine the $θ$-dependence of the fermionic correlators and determinants and find that a $CP$-breaking $θ$-term is generated dynamically. As an application we calculate the chiral condensate in multi-flavour $QED_2$ and the abelian projection of $QCD_2$. In the second model a condensate is generated in the limit where the number of colours, $N_c$, tends to infinity. We prove that the condensate in $QCD_2$ decreases with increasing bag radius $R$ at least as $\sim R^{-1/N_cN_f}$. Finally we determine the correlators of mesonic currents in $QCD_2$.

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A. Wipf, S. Duerr. 1994-12-15. Gauge Theories in a Bag. https://doi.org/10.1016/0550-3213(95)00114-8

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