skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Full QCD hadron spectroscopy with two flavors of dynamical Kogut-Susskind quarks on the lattice

Journal Article · · Physical Review, D (Particles Fields); (United States)
 [1];  [2];  [3];  [2];  [4]
  1. Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606 (Japan)
  2. National Laboratory for High Energy Physics (KEK), Ibaraki 305 (Japan)
  3. Faculty of Engineering, Yamanashi University, Kofu 400 (Japan)
  4. Institute of Physics, University of Tsukuba, Ibaraki 305 (Japan)

A full lattice QCD simulation is carried out with two flavors of Kogut-Susskind staggered dynamical quarks using lattices of a size ranging from 4[sup 4] to 20[sup 4] at the gauge coupling constant [beta]=6/[ital g][sup 2]=5.7 with the quark mass of [ital m][sub [ital q]]=0.01 and 0.02 in lattice units. Primary emphasis is given to the study of finite-lattice-size effects in the hadron mass spectrum. It is found that hadron masses suffer from substantial finite-size effects even for a lattice size of the order of 2 fm, showing the importance of a quantitative control of the effect for a comparison with the experimental spectrum at the accuracy of a few percent level. The finite-size correction is found to be well described by a power law in the lattice size, rather than an exponential form predicted by analytic formulas derived for point particles. It is suggested that the effect arises from the size of hadrons squeezed on a finite lattice. Finite-size effects on the realization of chiral symmetry are also studied. The behavior of the pion mass, the chiral condensate, and the mass splitting between parity partners all support a spontaneous breakdown of chiral symmetry for a large lattice size. Prediction from chiral Lagrangians on the size dependence of the chiral condensate does not describe the simulation results well, however, at least for the quark mass employed for the present study. Calculation of the pion decay constant with various relations derived from current algebra and partial conservation of axial-vector current gives [ital f][sub [pi]]=94(8)--105(9) MeV, with a method-dependent uncertainty contained within 10%. An examination is also made of the question of the dependence of hadron masses on hadron operators.

OSTI ID:
6876391
Journal Information:
Physical Review, D (Particles Fields); (United States), Vol. 47:10; ISSN 0556-2821
Country of Publication:
United States
Language:
English