Improving flavor symmetry in the Kogut-Susskind hadron spectrum
Tom Blum, Carleton DeTar, Steven Gottlieb, Urs M. Heller, James E. Hetrick, Kari Rummukainen, R. L. Sugar, Doug Toussaint, Matthew Wingate
Abstract
We study the effect of modifying the coupling of Kogut-Susskind quarks to the gauge field by replacing the link matrix in the quark action by a "fat link", or sum of link plus three-link paths. Flavor symmetry breaking, determined by the mass difference between the Goldstone and non-Goldstone local pions, is reduced by approximately a factor of two by this modification.