HEP Lattice·hep-lat
5 papers—4 primary·1 cross-listed·reconstructed*
M. Gürtler🇩🇪 · R. Horsley🇬🇧 · V. Linke🇩🇪 · H. Perlt🇩🇪 · P. E. L. Rakow🇬🇧 · G. Schierholz🇩🇪 · A. Schiller🇩🇪 · T. Streuer🇩🇪
We present results for the nucleon's axial charge g_A and the first moment <x> of the unpolarized parton distribution function from a simulation of quenched overlap fermions.
We report on the status of the ILDG Middleware Working Group.
M. Göckeler🇩🇪 · R. Horsley🇬🇧 · A. C. Irving🇬🇧 · D. Pleiter🇩🇪 · P. E. L. Rakow🇬🇧 · G. Schierholz🇩🇪 · H. Stüben🇩🇪
We present an update on our previous determination of the Lambda parameter in QCD. The main emphasis is on results for two flavours of light dynamical quarks, where we can now almost double the amount of data used, including values at smaller lattice spacings. The calculations are performed using improved Wilson fermions. Little change is found to previous numerical values.
We consider recent progress in algorithms for generating gauge field configurations that include the dynamical effects of light fermions. We survey what has been achieved in recent state-of-the-art computations, and examine the trade-offs between performance and control of systematic errors. We briefly review the use of polynomial and rational approximations in Hybrid Monte Carlo algorithms, and some of the theory of on-shell chiral fermions on the lattice. This provides a theoretical framework within which we compare algorithmic alternatives for their implementation; and again we examine the trade-offs between speed and error control.
Yu. A. Simonov🇷🇺 · J. A. Tjon🇺🇸
The shift of the p-wave meson mass due to coupling to the DK channel is calculated without fitting parameters using the chiral Lagrangian. As a result the original mass 2.490 MeV generically calculated in the relativistic quark models is shifted down to the experimental value 2317 MeV. With the same Lagrangian the shift of the radial excited level is much smaller, while the total width MeV and the width ratio is in contradiction with the state observed by SELEX group.
* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.