The $U(1)_A$ symmetry in QCD is anomalous. Its supposed to be broken by the instantons. Can anyone physically describe how does that happen?
$\begingroup$
$\endgroup$
1
-
$\begingroup$ See physics.stackexchange.com/q/150435/50583, physics.stackexchange.com/q/122206/50583 $\endgroup$– ACuriousMind ♦Commented Apr 9, 2019 at 17:11
Add a comment
|