Andreas S. Kronfeld

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This paper is a review of heavy quarks in lattice gauge theory, focusing on methodology. It includes a status report on some of the calculations that are relevant to heavy-quark spectroscopy and to flavor physics. The study of flavor-and CP-violation is a vital part of particle physics [1]. Often lattice QCD is needed to connect experimental measurements to(More)
The recently developed Symanzik-improved staggered-quark discretization allows unquenched lattice-QCD simulations with much smaller (and more realistic) quark masses than previously possible. To test this formalism, we compare experiment with a variety of nonperturbative calculations in QCD drawn from a restricted set of "gold-plated" quantities. We find(More)
The measured rate for D{s}{+}-->l+nu decays, where l is a muon or tau, is larger than the standard model prediction, which relies on lattice QCD, at the 3.8sigma level. We discuss how robust the theoretical prediction is, and we show that the discrepancy with experiment may be explained by a charged Higgs boson or a leptoquark.
We present the first lattice QCD calculation with realistic sea quark content of the D+-meson decay constant f(D+). We use the MILC Collaboration's publicly available ensembles of lattice gauge fields, which have a quark sea with two flavors (up and down) much lighter than a third (strange). We obtain f(D+)=201+/-3+/-17 MeV, where the errors are statistical(More)
We have calculated the decay constants of B and D mesons with lattice QCD. We use an O(a) improved action that takes light quark actions as a starting point, tuned so that it can be directly applied at the physical masses of the b and c quarks. Our results are fB = 164 +14 −11 ±8 MeV, fB s = 185 +13 − 8 ± 9 MeV, fD = 194 +14 −10 ± 10 MeV, and fD s = 213 +14(More)
We present the first three-flavor lattice QCD calculations for D-->pilnu and D-->Klnu semileptonic decays. Simulations are carried out using ensembles of unquenched gauge fields generated by the MILC Collaboration. With an improved staggered action for light quarks, we are able to simulate at light quark masses down to 1/8 of the strange mass. Consequently,(More)
This chapter reviews numerical simulations of quantum field theories based on stochastic quantization and the Langevin equation. The topics discussed include renormalization of finite step-size algorithms, Fourier acceleration, and the relation of the Langevin equation to hybrid stochastic algorithms and hybrid Monte Carlo. Invited chapter to appear in the(More)