Improved staggered fermion actions Standard staggered action has discretization errors ~ a 2 Eliminate those using higher order difference scheme The different staggered which flavors sit in different corners of the Brillouin zone Are completely equivalent in the free theory => flavor symmetry Not the case in the interacting theory: exchange with gluons with momenta ~ π/a can change the quark flavor (taste) as it brings it to another corner of the Brillouin zone Free quark propagator: Heller, Karsch, Sturm, PRD60 (1999) 114502 18
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