Massive fermions in lattice gauge theory

Apr, 1996
54 pages
Published in:
  • Phys.Rev.D 55 (1997) 3933-3957
e-Print:
Report number:
  • FERMILAB-PUB-96-074-T,
  • ILL-TH-96-1

Citations per year

1996200320102017202405101520253035
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 evaluated for arbitrary fermion massmqm_q, 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 b_n(m_qa)[\vek{p}a]~{s_n}, where \vek{p} is a momentum characteristic of the system under study, sns_n is related to the dimension of the nnth interaction, and bn(mqa)b_n(m_qa) is a bounded function, numerically always\order(1) or less. In heavy-quark systems \vek{p} is typically rather smaller than the fermion massmqm_q. Therefore, artifacts of order (mqa) s(m_qa)~s do not arise, even when m_qa\gsim1. An important by-product of our analysis is an interpretation of the Wilson and Sheikholeslami-Wohlert actions applied to nonrelativistic fermions.
  • 12.38.Gc
  • 11.15.Ha
  • 12.39.Hg
  • gauge field theory
  • lattice field theory
  • fermion: massive
  • massive: fermion
  • Feynman graph: higher-order
  • coupling
  • mass dependence