Eur. Phys. J. C (2007) 51: 875-881
https://doi.org/10.1140/epjc/s10052-007-0336-1

Regular Article - Theoretical Physics

Flavor symmetry breaking and scaling for improved staggered actions in quenched QCD

¹ Physics Department, Columbia University, New York, NY, 10027, USA
² Physics Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
³ RIKEN-BNL Research Center, Brookhaven National Laboratory, Upton, NY, 11973, USA
⁴ Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100, Copenhagen, Denmark

^* e-mail: michaelc@phys.columbia.edu

Received: 17 April 2007
Published online: 1 August 2007

Abstract

We present a study of the flavor symmetry breaking in the pion spectrum for the p4-improved fermion action. Three different variants of the p4 action – p4fat3, p4fat7, and p4fat7tad – are compared to the Asqtad and naive staggered actions. To study the pattern of symmetry breaking, we measure all 15 pion masses in the four-flavor staggered theory. The measurements are done on a quenched gauge background, generated using a one-loop improved Symanzik action with β=10/g²=7.40, 7.75, and 8.00, corresponding to lattice spacings of approximately a= 0.31 fm, 0.21 fm, and 0.14 fm.