Abstract

The partition function of QCD is analyzed for an arbitrary number of flavors, N_f, and arbitrary quark masses including the contributions from all topological sectors in the Leutwyler--Smilga regime. For given N_f and arbitrary vacuum angle, θ, the partition function can be reduced to N_f-2 angular integrations of single Bessel functions. For two and three flavors, the θdependence of the QCD vacuum is studied in detail. For N_f= 2 and 3, the chiral condensate decreases monotonically as θincreases from zero to πand the chiral condensate develops a cusp at θ=πfor degenerate quark masses in the macroscopic limit. We find a discontinuity at θ=πin the first derivative of the energy density with respect to θfor degenerate quark masses. This corresponds to the first--order phase transition in which CP is spontaneously broken, known as Dashen's phenomena.

Explore this paper’s authors, topics and related work.

Building this map preview

BZPEER is loading the nearby papers, people, topics and institutions for this page.

Reviews 0

Write a reviewWrite

No reviews yet.

Discussion 0

Add a commentWrite

No comments yet.