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arXiv · hep-lat/0409016

Bulk first-order phase transition in three-flavor lattice QCD with $O(a)$-improved Wilson fermion action at zero temperature

JLQCD collaboration·S. Aoki·M. Fukugita·S. Hashimoto·K-I. Ishikawa·N. Ishizuka·Y. Iwasaki·K. Kanaya·T. Kaneko·Y. Kuramashi·M. Okawa·N. Tsutsui·A. Ukawa·N. Yamada·T. Yoshié
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Abstract

Three-flavor QCD simulation with the $O(a)$-improved Wilson fermion action is made employing an exact fermion algorithm developed for odd number of quark flavors. For the plaquette gauge action, an unexpected first-order phase transition is found in the strong coupling regime ($β\lesssim$ 5.0) at relatively heavy quark masses ($m_{\mathrm{PS}}/m_{\mathrm{V}}\sim$ 0.74--0.87). Strong metastability persists on a large lattice of size $12^3\times 32$, which indicates that the transition has a bulk nature. The phase gap becomes smaller toward weaker couplings and vanishes at $β\simeq 5.0$, which corresponds to a lattice spacing $a\simeq$ 0.1 fm. The phase transition is not found if the improved gauge actions are employed. Our results imply that realistic simulations of QCD with three flavors of dynamical Wilson-type fermions at lattice spacings in the range $a=$ 0.1--0.2 fm require use of improved gauge actions. Possible origins of the phase transition is discussed.

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JLQCD collaboration, S. Aoki, M. Fukugita, S. Hashimoto, K-I. Ishikawa, N. Ishizuka, Y. Iwasaki, K. Kanaya, T. Kaneko, Y. Kuramashi, M. Okawa, N. Tsutsui, A. Ukawa, N. Yamada, T. Yoshié. 2004-09-04. Bulk first-order phase transition in three-flavor lattice QCD with $O(a)$-improved Wilson fermion action at zero temperature. https://doi.org/10.1103/physrevd.72.054510

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