## Abstract

This paper presents a formulation of lattice fermions applicable to all quark masses, large and small. We incorporate interactions from previous light-fermion and heavy-fermion methods, and thus ensure a smooth connection to these limiting cases. The couplings in improved actions are obtained for arbitrary fermion mass [Formula presented] without expansions around small- or large-mass limits. We treat both the action and external currents. By interpreting on-shell improvement criteria through the lattice theory's Hamiltonian, one finds that cutoff artifacts factorize into the form [Formula presented] where p is a momentum characteristic of the system under study, [Formula presented] is related to the dimension of the [Formula presented]th interaction, and [Formula presented] is a bounded function, numerically always of order 1 or less. In heavy-quark systems p is typically rather smaller than the fermion mass [Formula presented] Therefore, artifacts of order [Formula presented] do not arise, even when [Formula presented]. An important by-product of our analysis is an interpretation of the Wilson and Sheikholeslami-Wohlert actions applied to nonrelativistic fermions.

Original language | English (US) |
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Pages (from-to) | 3933-3957 |

Number of pages | 25 |

Journal | Physical Review D - Particles, Fields, Gravitation and Cosmology |

Volume | 55 |

Issue number | 7 |

DOIs | |

State | Published - 1997 |

## ASJC Scopus subject areas

- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)