Polynomial hybrid Monte Carlo algorithm for lattice QCD with an odd number of flavors

JLQCD Collaboration

Aoki Sinya

Burkhalter Rudolf

Fukugita Masataka

Hashimoto Shoji

Ishikawa Kenichi

Ishizuka Naruhito

Iwasaki Yoichi

Kanaya Kazuyuki

Kaneko Takashi

Kuramashi Yoshinobu

Okawa Masanori

Onogi Tetsuya

Tominaga Shin-ichi

Tsutsui Naoto

Ukawa Akira

Yamada Norikazu

Yoshie Tomoteru

Physical Review D

We present a polynomial hybrid Monte Carlo (PHMC) algorithm for lattice QCD with odd numbers of flavors of O(a)-improved Wilson quark action. The algorithm makes use of the non-Hermitian Chebyshev polynomial to approximate the inverse square root of the fermion matrix required for an odd number of flavors. The systematic error from the polynomial approximation is removed by a noisy Metropolis test for which a new method is developed. Investigating the property of our PHMC algorithm in the Nf=2 QCD case, we find that it is as efficient as the conventional HMC algorithm for a moderately large lattice size (163×48) with intermediate quark masses (mPS/mV∼0.7–0.8). We test our odd-flavor algorithm through extensive simulations of two-flavor QCD treated as an Nf=1+1 system, and comparing the results with those of the established algorithms for Nf=2 QCD. These tests establish that our PHMC algorithm works on a moderately large lattice size with intermediate quark masses (163×48,mPS/mV∼0.7–0.8). Finally we experiment with the (2+1)-flavor QCD simulation on small lattices (43×8 and 83×16), and confirm the agreement of our results with those obtained with the R algorithm and extrapolated to a zero molecular dynamics step size.

eng

American Physical Society

Copyright (c) 2002 The American Physical Society.

[ISSN] 1550-7998

[DOI] 10.1103/PhysRevD.65.094507

[NCID] AA00773624

[DOI] http://dx.doi.org/10.1103/PhysRevD.65.094507