Taste breaking and the topological susceptibility in lattice quantum chromodynamics

In the process of measuring the topological susceptibility, we test a currently popular computer algorithm that uses staggered fermions in the simulations of quantum chromodynamics (QCD) with dynamical quarks in a lattice environment. As staggered fermions are used in the simulations, an unwanted extra degree of freedom called "tastes" are present too. These tastes need to be removed and their effects corrected for. A way this effect has been corrected for is by taking the 'fourth root" of the fermion determinant. The fermion determinant is a crucial step in the numerical calculations used to model QCD. Taking the "fourth root" gives the correct weight to the fermion determinant and correctly counts the number of fermions to match the number in the continuum.