"A precise determination of the
charm quark's mass in quenched QCD"
Relatore: Dr Stefan Sint
CERN - Ginevra
8 Maggio 2002 - Ore 16.30
I report on a recent lattice computation of the charmed quark mass, using the mass of the D_s meson as input
from experiment. All errors are controlled, with the exception of the quenched (or valence) approximation.
In particular, renormalization and O(a) improvement are implemented non-perturbatively, and the continuum limit
is taken. For fixed experimental input the total error for the charm quark mass is around 4 percent, which is
clearly smaller than the quenching error. A first idea of the latter is obtained by allowing for a ``quenched
scale ambiguity" of 10 percent. While the charm quark mass is shifted by about 8 percent, this effect largely
cancels in the mass ratio M_charm/M_strange.