Topological susceptibility from the overlap
Abstract
The chiral symmetry at finite lattice spacing of GinspargWilson fermionic actions constrains the renormalization of the lattice operators; in particular, the topological susceptibility does not require any renormalization, when using a fermionic estimator to define the topological charge. Therefore, the overlap formalism appears as an appealing candidate to study the continuum limit of the topological susceptibility while keeping the systematic errors under theoretical control. We present results for the SU(3) pure gauge theory using the index of the overlap Dirac operator to study the topology of the gauge configurations. The topological charge is obtained from the zero modes of the overlap and using a new algorithm for the spectral flow analysis. A detailed comparison with cooling techniques is presented. Particular care is taken in assessing the systematic errors. Relatively high statistics (500 to 1000 independent configurations) yield an extrapolated continuum limit with errors that are comparable with other methods. Our current value from the overlap is chi^{1/4} = 188+/12+/5 MeV.
 Publication:

Journal of High Energy Physics
 Pub Date:
 February 2004
 DOI:
 10.1088/11266708/2004/02/003
 arXiv:
 arXiv:heplat/0309145
 Bibcode:
 2004JHEP...02..003D
 Keywords:

 Nonperturbative Effects Lattice Gauge Field Theories Lattice QCD;
 High Energy Physics  Lattice
 EPrint:
 18 pages, 7 figures