[Show abstract][Hide abstract] ABSTRACT: Central and spin-spin potentials for charmonium, constructed from
Nambu-Bethe-Salpeter amplitudes in lattice simulations of full QCD, are matched
with results from perturbative QCD at an appropriate distance scale. This
matching is made possible by defining the perturbative potentials through
Fourier transforms with a low-momentum cutoff. The central (spin-independent)
potential is compared with potentials derived from an expansion in powers of
the inverse quark mass. A well-controlled continuation of the charmonium
spin-spin potential from lattice QCD to short distances is performed. The mass
splittings of the charmonium singlet and triplet states below the open charm
threshold, obtained from the matched spin-spin potential, are in good agreement
with the experimental values.
[Show abstract][Hide abstract] ABSTRACT: The heavy quark-antiquark potential is accessible in perturbative QCD and in
lattice simulations. The perturbative short-distance part of the potential is
contructed via a restricted Fourier transform, covering the momentum region
where perturbative QCD is applicable. We show that for the leading order static
term as well as for the mass dependent corrections, the perturbative part can
be matched at intermediate distances with results from lattice QCD. From these
matched potentials, quarkonium spectra with a single free parameter (the heavy
quark mass) are derived and compared with empirical spectra. Furthermore, charm
and bottom quark masses are deduced.
[Show abstract][Hide abstract] ABSTRACT: The heavy quark-antiquark potential is an important topic in QCD that involves perturbative as well as non-perturbative methods. We construct the perturbative short-distance part of the potential in coordinate space via a subtracted Fourier transform, covering the momentum region where perturbative QCD is applicable. This potential is matched at intermediate distances to the non-perturbative long distance part from lattice QCD simulations. In addition to the static potential, quark mass dependent contributions and their effects on the quarkonium spectrum are discussed. Furthermore we derive charm and bottom quark masses in this approach.
[Show abstract][Hide abstract] ABSTRACT: An updated heavy quark-antiquark potential is constructed by matching the
short-distance perturbative part to long-distance lattice QCD results at an
intermediate r scale. The static potential and the order 1/m potential are both
analyzed in this way. Effects if order 1/m in charmonium and bottomonium
spectra are discussed in comparison. Charm and bottom quark masses are deduced
from the spectra and related to the quark masses of other schemes.
[Show abstract][Hide abstract] ABSTRACT: The heavy quark-antiquark potential in perturbative QCD is subject to ambiguities. We show how to derive a well-defined and stable short-distance potential that can be matched to results from lattice QCD simulations at intermediate distances. The static potential as well as the order 1/m potential are discussed. Comment: 2 pages, 2 figures, Proceedings of the 8th Conference on Quark Confinement and the Hadron Spectrum, September 1-6, 2008, Mainz, Germany