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Low-lying mode contribution to the quenched meson correlators in the epsilon-regime

Hidenori Fukaya·Shoji Hashimoto·Kenji Ogawa
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Abstract

We present a quenched calculation of meson correlators with the overlap fermion at very small masses 2.6--13 MeV. In this region the pion Compton wavelength is larger than our lattice size L\simeq 1.23fm and the system is in the so-called epsilon-regime of chiral perturbation theory. We found that the scalar and pseudo-scalar correlators are precisely approximated by a few hundred low-lying fermion eigenmodes in this regime, whereas axial-vector correlator receives significant contributions from higher eigenmodes. We also measure the disconnected pseudo-scalar correlator, which is well saturated with the low-lying modes. Matching these lattice data with the one-loop expressions for the correlators in quenched chiral perturbation theory, we evaluate the decay constant F_pi and the chiral condensate Sigma as well as the parameters m_0 and alpha, which describe the artifacts of the quenched approximation.

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Hidenori Fukaya, Shoji Hashimoto, Kenji Ogawa. 2005-06-01. Low-lying mode contribution to the quenched meson correlators in the epsilon-regime. https://doi.org/10.1143/ptp.114.451

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