Ginsparg-Wilson pions scattering in a sea of staggered quarks

Journal Article · Sat Apr 01 04:00:00 EST 2006 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.73.074510· OSTI ID:20782829

Chen, J -W ^[1]; O'Connell, Donal ^[2]; Van de Water, Ruth; Walker-Loud, Andre ^[3]

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1. Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China)
2. California Institute of Technology, Pasadena, California 91125 (United States)
3. Department of Physics, University of Washington, Box 351560, Seattle, Washington 98195-1560 (United States)

We calculate isospin 2 pion-pion scattering in chiral perturbation theory for a partially quenched, mixed action theory with Ginsparg-Wilson valence quarks and staggered sea quarks. We point out that for some scattering channels, the power-law volume dependence of two-pion states in nonunitary theories such as partially quenched or mixed action QCD is identical to that of QCD. Thus one can extract infinite-volume scattering parameters from mixed action simulations. We then determine the scattering length for both 2 and 2+1 sea quarks in the isospin limit. The scattering length, when expressed in terms of the pion mass and the decay constant measured on the lattice, has no contributions from mixed valence-sea mesons, thus it does not depend upon the parameter, C{sub Mix}, that appears in the chiral Lagrangian of the mixed theory. In addition, the contributions which nominally arise from operators appearing in the mixed action O(a{sup 2}m{sub q}) Lagrangian exactly cancel when the scattering length is written in this form. This is in contrast to the scattering length expressed in terms of the bare parameters of the chiral Lagrangian, which explicitly exhibits all the sicknesses and lattice spacing dependence allowed by a partially quenched mixed action theory. These results hold for both 2 and 2+1 flavors of sea quarks.

• OSTI ID: 20782829
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 7 Vol. 73; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ACTION INTEGRAL
CHIRAL SYMMETRY
CHIRALITY
COMPUTERIZED SIMULATION
FLAVOR MODEL
ISOSPIN
LAGRANGIAN FIELD THEORY
LAGRANGIAN FUNCTION
LATTICE FIELD THEORY
PARTICLE DECAY
PERTURBATION THEORY
PION-PION INTERACTIONS
PIONS
QUANTUM CHROMODYNAMICS
QUARKS
REST MASS
SCATTERING
SCATTERING LENGTHS
VALENCE