Taste symmetry breaking with hypercubic-smeared staggered fermions

Journal Article · Thu May 01 04:00:00 EDT 2008 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.77.094508· OSTI ID:21250138

Bae, Taegil; Adams, David H; Kim, Hyung-Jin; Kim, Jongjeong; Kim, Kwangwoo; Lee, Weonjong ^[1]; Jung, Chulwoo ^[2]; Sharpe, Stephen R ^[3]

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1. Frontier Physics Research Division and Center for Theoretical Physics, Department of Physics and Astronomy, Seoul National University, Seoul, 151-747 (Korea, Republic of)
2. Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)
3. Physics Department, University of Washington, Seattle, Washington 98195-1560 (United States)

We study the impact of hypercubic (HYP) smearing on the size of taste-breaking for staggered fermions, comparing to unimproved and to asqtad-improved staggered fermions. As in previous studies, we find a substantial reduction in taste-breaking compared to unimproved staggered fermions (by a factor of 4-7 on lattices with spacing a{approx_equal}0.1 fm). In addition, we observe that discretization effects of next-to-leading order in the chiral expansion (O(a{sup 2}p{sup 2})) are markedly reduced by HYP smearing. Compared to asqtad valence fermions, we find that taste-breaking in the pion spectrum is reduced by a factor of 2.5-3, down to a level comparable to the expected size of generic O(a{sup 2}) effects. Our results suggest that, once one reaches a lattice spacing of a{approx_equal}0.09 fm, taste-breaking will be small enough after HYP smearing that one can use a modified power counting in which O(a{sup 2})<<O(p{sup 2}), simplify fitting to phenomenologically interesting quantities.

• OSTI ID: 21250138
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 9 Vol. 77; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CHIRALITY
EXPANSION
FERMIONS
PIONS
REDUCTION
SPECTRA
SYMMETRY BREAKING