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arXiv · 1211.2282

Auxiliary field Monte-Carlo study of the QCD phase diagram at strong coupling

Akira Ohnishi·Terukazu Ichihara·Takashi Z. Nakano
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Abstract

We investigate the QCD phase diagram in the strong coupling limit by using a newly developed auxiliary field Monte-Carlo (AFMC) method. Starting from an effective action in the leading order of the 1/g^2 and 1/d expansion with one species of unrooted staggered fermion, we solve the many-body problem exactly by introducing the auxiliary fields and integrating out the temporal links and quark fields. We have a sign problem in AFMC, which is different from the original one in finite density lattice QCD. For low momentum auxiliary field modes, a complex phase cancellation mechanism exists, and the sign problem is not serious on a small lattice. Compared with the mean field results, the transition temperature is found to be reduced by around 10 % and the hadron phase is found to be extended in the larger chemical potential direction by around 20 %, as observed in the monomer-dimer-polymer (MDP) simulations.

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Akira Ohnishi, Terukazu Ichihara, Takashi Z. Nakano. 2012-11-10. Auxiliary field Monte-Carlo study of the QCD phase diagram at strong coupling. https://arxiv.org/abs/1211.2282

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