Charmed Meson Spectroscopy and Matrix Elements with an O(a)-Improved Clover Fermion Action

TL;DR

This paper reports on lattice QCD calculations of meson spectra and decay constants using an O(a)-improved fermion action, showing enhanced hyperfine splitting and insights into heavy-light meson decay constants.

Contribution

It introduces preliminary results using an O(a)-improved Clover fermion action for heavy-light and heavy-heavy mesons, comparing with Wilson fermion results and analyzing scaling corrections.

Findings

Hyperfine splitting in charmonium is 1.83(15) times larger with the improved action.

Decay constant f_B shows about 20% non-scaling corrections to HQET.

Results are compared across different lattice sizes and beta values.

Abstract

We present preliminary results for the spectrum and decay matrix elements for heavy-light and heavy-heavy mesons, obtained on the 64-node Meiko Computing Surface at the University of Edinburgh. Quark propagators are computed with an O(a)-improved fermion action on 24^3x48 lattices at beta = 6.2, using three values of the quark mass up to around the strange quark mass, and four values of the quark mass in the region of the charm quark mass. We compare results for the hyperfine splitting in charmonium with those obtained using the conventional Wilson fermion action and find that the splitting is 1.83(15) times larger with the improved action. Our measurements of f_B indicate non-scaling corrections of the order of 20% to the Heavy Quark Effective Theory expectation. A comparison is made with results obtained on 16^3x48 lattices at beta = 6.0.