arXiv subjects

Gregory W. Kilcup

Publications and source records attributed to Gregory W. Kilcup.

4 recordsLinked to original sources

arXiv2002

Gasser-Leutwyler coefficients: A progress report

Last year, we reported our first results on the determination of Gasser-Leutwyler coefficients using partially quenched lattice QCD with three flavors of dynamical staggered quarks. We give an update on our progress in determining two of these coefficients, including an exhaustive effort to estimate all sources of systematic error. At this conference, we have heard about algorithmic techniques to reduce staggered flavor symmetry breaking and a method to incorporate staggered flavor breaking into the partially quenched chiral Lagrangian. We comment on our plans to integrate these developments into our ongoing program.

hep-lat↗

arXiv2002

Is strong CP invariance due to a massless up quark?

A standing mystery in the Standard Model is the unnatural smallness of the strong CP violating phase. A massless up quark has long been proposed as one potential solution. A lattice calculation of the constants of the chiral Lagrangian essential for the determination of the up quark mass, 2 alpha_8 - alpha_5, is presented. We find 2 alpha_8 - alpha_5 = 0.29 +/- 0.18, which corresponds to m_u / m_d = 0.410 +/- 0.036. This is the first such calculation using a physical number of dynamical light quarks, N_f = 3.

hep-lat↗

arXiv1998

Status of the QCDSP project

We describe the completed 8,192-node, 0.4Tflops machine at Columbia as well as the 12,288-node, 0.6Tflops machine assembled at the RIKEN Brookhaven Research Center. Present performance as well as our experience in commissioning these large machines is presented. We outline our on-going physics program and explain how the configuration of the machine is varied to support a wide range of lattice QCD problems, requiring a variety of machine sizes. Finally a brief discussion is given of future prospects for large-scale lattice QCD machines.

hep-lat↗

arXiv1997

QCDSP - A status report

The QCDSP machine at Columbia University has grown to 2,048 nodes achieving a peak speed of 100 Gigaflops. Software for quenched and Hybrid Monte Carlo (HMC) evolution schemes has been developed for staggered fermions, with support for Wilson and clover fermions under development. We provide an overview of the runtime environment, the current status of the QCDSP construction program and preliminary results not presented elsewhere in these proceedings.

hep-lat↗