出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We calculate the kaon B-parameter, BK, to next-to-leading order in staggered chiral perturbation
theory. We extend the usual power counting to include the effects of using perturbative (rather
than non-perturbative) matching factors. Taste breaking enters through the O(a2) terms in the
effective action, through mixing with higher-dimension operators, and through the truncation of
matching factors. These effects cause mixing with several additional operators, complicating the
chiral and continuum extrapolations. We summarize the results here; all details can be found in
Ref. [1].
