{"paper":{"title":"Exploring QCD at small sea quark masses with improved Wilson-type quarks","license":"","headline":"","cross_cats":[],"primary_cat":"hep-lat","authors_text":"A. Ukawa, CP-PACS Collaboration: Y. Namekawa, K-I. Ishikawa, K. Kanaya, M. Fukugita, M. Okawa, N. Ishizuka, S. Aoki, T. Kaneko, T. Umeda, T. Yoshi\\'e, V.I. Lesk, Y. Iwasaki, Y. Kuramashi, Y. Taniguchi","submitted_at":"2002-09-05T08:54:44Z","abstract_excerpt":"We explore the region of small sea quark masses below $m_{PS}/m_V=0.5$ in two-flavor QCD using a mean-field improved clover quark action and an RG-improved gauge action at $a \\simeq 0.2$ fm on $12^3 \\times 24$ and $16^3 \\times 24$ lattices. We find that instability of the standard BiCGStab algorithm at small quark masses can be mostly removed by the BiCGStab(DS-$L$) algorithm, which employs $L$-th minimal residual polynomials with a dynamical selection of $L$. We also find singular spikes of $\\Delta H$ in the HMC algorithm at moderate values of $\\Delta\\tau$. Nature of the spike is studied. We "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"hep-lat/0209073","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"}