Massive fermions in lattice gauge theory
Abstract
This paper presents a formulation of lattice fermions applicable to all quark masses, large and small. We incorporate interactions from previous lightfermion and heavyfermion methods, and thus ensure a smooth connection to these limiting cases. The couplings in improved actions are obtained for arbitrary fermion mass m_{q}, without expansions around small or largemass limits. We treat both the action and external currents. By interpreting onshell improvement criteria through the lattice theory's Hamiltonian, one finds that cutoff artifacts factorize into the form b_{n}(m_{q}a)[pa]^{sn} where p is a momentum characteristic of the system under study, s_{n} is related to the dimension of the nth interaction, and b_{n}(m_{q}a) is a bounded function, numerically always of order 1 or less. In heavyquark systems p is typically rather smaller than the fermion mass m_{q}. Therefore, artifacts of order (m_{q}a)^{s} do not arise, even when m_{q}a>~1. An important byproduct of our analysis is an interpretation of the Wilson and SheikholeslamiWohlert actions applied to nonrelativistic fermions.
 Publication:

Physical Review D
 Pub Date:
 April 1997
 DOI:
 10.1103/PhysRevD.55.3933
 arXiv:
 arXiv:heplat/9604004
 Bibcode:
 1997PhRvD..55.3933E
 Keywords:

 11.15.Ha;
 12.38.Gc;
 12.39.Hg;
 Lattice gauge theory;
 Lattice QCD calculations;
 Heavy quark effective theory;
 High Energy Physics  Lattice;
 High Energy Physics  Phenomenology
 EPrint:
 54 pages