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Perturbative matching of staggered four-fermion operators with hypercubic fat links

Weonjong Lee·Stephen Sharpe
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Abstract

We calculate the one-loop matching coefficients between continuum and lattice four-fermion operators for lattice operators constructed using staggered fermions and improved by the use of fattened links. In particular, we consider hypercubic fat links and SU(3) projected Fat-7 links, and their mean-field improved versions. We calculate only current-current diagrams, so that our results apply for operators whose flavor structure does not allow ``eye-diagrams''. We present general formulae, based on two independent approaches, and give numerical results for the cases in which the operators have the taste (staggered flavor) of the pseudo-Goldstone pion. We find that the one-loop corrections are reduced down to the 10-20% level, resolving the problem of large perturbative corrections for staggered fermion calculations of matrix elements.

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Weonjong Lee, Stephen Sharpe. 2003-06-15. Perturbative matching of staggered four-fermion operators with hypercubic fat links. https://doi.org/10.1103/physrevd.68.054510

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