f_B for Various Actions : Approaching the Continuum Limit with Dynamical Fermions

TL;DR

This paper investigates pseudoscalar decay constants of heavy-light mesons using various fermion actions and approaches the continuum limit with dynamical fermions, comparing quenched and unquenched results.

Contribution

It systematically compares different fermion actions and their continuum extrapolations for heavy-light meson decay constants, including dynamical fermion effects.

Findings

Nonperturbatively improved clover action reduces systematic errors.

Fattening effects influence decay constant calculations.

Continuum extrapolation is feasible with dynamical fermions.

Abstract

We present results for pseudoscalar decay constants of heavy-light mesons using both quenched and N_f = 2 dynamical fermion configurations. A variety of fermion actions is investigated : Wilson, nonperturbative clover, and fat-link clover. For heavy quarks the Fermilab formalism is applied. In the quenched approximation, results with the nonperturbatively improved clover action of the Alpha collaboration allow us to study the systematic error of the continuum extrapolation from the Wilson action. In addition, we use quenched configurations to explore the effects of fattening. The lessons from the quenched analyses are then applied to data with dynamical fermions, where both Wilson and fat-link clover actions have been used. This allows us to attempt a continuum extrapolation of the dynamical results.