TY - JOUR

T1 - Topological susceptibility from the overlap

AU - Del Debbio, Luigi

AU - Pica, Claudio

PY - 2003

Y1 - 2003

N2 - The chiral symmetry at finite lattice spacing of Ginsparg-Wilson 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
$\chi^{1/4} = 188 \pm 12 \pm 5 \MeV$.

AB - The chiral symmetry at finite lattice spacing of Ginsparg-Wilson 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
$\chi^{1/4} = 188 \pm 12 \pm 5 \MeV$.

KW - hep-lat

U2 - 10.1088/1126-6708/2004/02/003

DO - 10.1088/1126-6708/2004/02/003

M3 - Journal article

VL - 2004

JO - Journal of High Energy Physics (Online)

JF - Journal of High Energy Physics (Online)

SN - 1126-6708

IS - 2

ER -