### Abstract

As an effective model corresponding to Z3-symmetric QCD (Z3-QCD), we construct a Z3-symmetric effective Polyakov-line model (Z3-EPLM) by using the logarithmic fermion effective action. Since Z3-QCD tends to QCD in the zero-temperature limit, Z3-EPLM also agrees with the ordinary effective Polyakov-line model (EPLM) there; note that (ordinary) EPLM does not possess Z3 symmetry. Our main purpose is to discuss a sign problem appearing in Z3-EPLM. The action of Z3-EPLM is real when not only the Polyakov line is real but also its Z3 images. This suggests that the sign problem becomes milder in Z3-EPLM than in EPLM. In order to confirm this suggestion, we do lattice simulations for both EPLM and Z3-EPLM by using the reweighting method with the phase quenched approximation. In the low-temperature region, the sign problem is milder in Z3-EPLM than in EPLM. We also propose a new reweighting method. This makes the sign problem very weak in Z3-EPLM.

Original language | English |
---|---|

Article number | 074031 |

Journal | Physical Review D |

Volume | 96 |

Issue number | 7 |

DOIs | |

Publication status | Published - Oct 27 2017 |

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### All Science Journal Classification (ASJC) codes

- Physics and Astronomy (miscellaneous)

### Cite this

*Physical Review D*,

*96*(7), [074031]. https://doi.org/10.1103/PhysRevD.96.074031

**Sign problem in a Z3 -symmetric effective Polyakov-line model.** / Hirakida, Takehiro; Sugano, Junpei; Kouno, Hiroaki; Takahashi, Junichi; Yahiro, Masanobu.

Research output: Contribution to journal › Article

*Physical Review D*, vol. 96, no. 7, 074031. https://doi.org/10.1103/PhysRevD.96.074031

}

TY - JOUR

T1 - Sign problem in a Z3 -symmetric effective Polyakov-line model

AU - Hirakida, Takehiro

AU - Sugano, Junpei

AU - Kouno, Hiroaki

AU - Takahashi, Junichi

AU - Yahiro, Masanobu

PY - 2017/10/27

Y1 - 2017/10/27

N2 - As an effective model corresponding to Z3-symmetric QCD (Z3-QCD), we construct a Z3-symmetric effective Polyakov-line model (Z3-EPLM) by using the logarithmic fermion effective action. Since Z3-QCD tends to QCD in the zero-temperature limit, Z3-EPLM also agrees with the ordinary effective Polyakov-line model (EPLM) there; note that (ordinary) EPLM does not possess Z3 symmetry. Our main purpose is to discuss a sign problem appearing in Z3-EPLM. The action of Z3-EPLM is real when not only the Polyakov line is real but also its Z3 images. This suggests that the sign problem becomes milder in Z3-EPLM than in EPLM. In order to confirm this suggestion, we do lattice simulations for both EPLM and Z3-EPLM by using the reweighting method with the phase quenched approximation. In the low-temperature region, the sign problem is milder in Z3-EPLM than in EPLM. We also propose a new reweighting method. This makes the sign problem very weak in Z3-EPLM.

AB - As an effective model corresponding to Z3-symmetric QCD (Z3-QCD), we construct a Z3-symmetric effective Polyakov-line model (Z3-EPLM) by using the logarithmic fermion effective action. Since Z3-QCD tends to QCD in the zero-temperature limit, Z3-EPLM also agrees with the ordinary effective Polyakov-line model (EPLM) there; note that (ordinary) EPLM does not possess Z3 symmetry. Our main purpose is to discuss a sign problem appearing in Z3-EPLM. The action of Z3-EPLM is real when not only the Polyakov line is real but also its Z3 images. This suggests that the sign problem becomes milder in Z3-EPLM than in EPLM. In order to confirm this suggestion, we do lattice simulations for both EPLM and Z3-EPLM by using the reweighting method with the phase quenched approximation. In the low-temperature region, the sign problem is milder in Z3-EPLM than in EPLM. We also propose a new reweighting method. This makes the sign problem very weak in Z3-EPLM.

UR - http://www.scopus.com/inward/record.url?scp=85033229776&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85033229776&partnerID=8YFLogxK

U2 - 10.1103/PhysRevD.96.074031

DO - 10.1103/PhysRevD.96.074031

M3 - Article

AN - SCOPUS:85033229776

VL - 96

JO - Physical Review D

JF - Physical Review D

SN - 2470-0010

IS - 7

M1 - 074031

ER -