{"paper":{"title":"Kaon $B$-parameter from improved staggered fermions in $N_f=2+1$ QCD","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["hep-ph"],"primary_cat":"hep-lat","authors_text":"Boram Yoon, Chulwoo Jung, Hyung-Jin Kim, Jangho Kim, Jongjeong Kim, Kwangwoo Kim, Stephen R. Sharpe, Sunghee Kim, SWME Collaboration, Taegil Bae, Weonjong Lee, Yong-Chull Jang","submitted_at":"2011-11-24T09:05:57Z","abstract_excerpt":"We present a calculation of the kaon $B$-parameter, $B_K$, using lattice QCD. We use improved staggered valence and sea fermions, the latter generated by the MILC collaboration with $N_f=2+1$ light flavors. To control discretization errors, we use four different lattice spacings ranging down to $a\\approx 0.045\\;$fm. The chiral and continuum extrapolations are done using SU(2) staggered chiral perturbation theory. Our final result is $\\hat{B}_K = 0.727 \\pm 0.004 (\\text{stat}) \\pm 0.038 (\\text{sys})$, where the dominant systematic error is from our use of truncated (one-loop) matching factors."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1111.5698","kind":"arxiv","version":3},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}