Nonperturbative determination of the O(a) improvement coefficient cA and the scaling of f(pi) and m(MS)over-bar

Collins, S.,, Davies, C.T.H. , Lepage, G.P. and Shigemitsu, J. (2003) Nonperturbative determination of the O(a) improvement coefficient cA and the scaling of f(pi) and m(MS)over-bar. Physical Review D, 67(1), art 014504. (doi: 10.1103/PhysRevD.67.014504)

Abstract

We report on an investigation of the LANL method for determining the O(a) improvement coefficient c(A) nonperturbatively. We find we are able to extract reliable estimates for the coefficient using this method. However, our study of systematic errors shows that for very accurate determinations of c(A), the smearing function must be tuned to keep the O(a) ambiguity in c(A) fixed as beta varies. Consistency was found with previous results from the LANL group and (within fairly large errors) 1-loop perturbation theory; c(A) does not change significantly over the range beta=5.93- 6.2. The big difference between our results and those of the ALPHA Collaboration, around beta=6.0, shows that the O(a) differences in c(A) between the different methods can be large. We find that the lattice spacing dependence of f(pi) and the renormalized quark mass is much smaller using our values of c(A) compared to those of the ALPHA Collaboration.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Shigemitsu, Prof Junko and Davies, Professor Christine
• Authors: Collins, S.,, Davies, C.T.H., Lepage, G.P., and Shigemitsu, J.
• Subjects: Q Science > QC Physics
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Physical Review D
• Publisher: American Physical Society
• ISSN: 1550-7998
• ISSN (Online): 1089-4918