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arXiv · 1111.0417

Chiral interpolation in a finite volume

JLQCD Collaboration·H. Fukaya·S. Aoki·S. Hashimoto·T. Kaneko·H. Matsufuru·J. Noaki·T. Onogi·N. Yamada
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Abstract

A simulation of lattice QCD at (or even below) the physical pion mass is feasible on a small lattice size of \sim 2 fm. The results are, however, subject to large finite volume effects. In order to precisely understand the chiral behavior in a finite volume, we develop a new computational scheme to interpolate the conventional epsilon and p regimes within chiral perturbation theory. In this new scheme, we calculate the two-point function in the pseudoscalar channel, which is described by a set of Bessel functions in an infra-red finite way as in the epsilon regime, while chiral logarithmic effects are kept manifest as in the p regime. The new ChPT formula is compared to our 2+1- flavor lattice QCD data near the physical up and down quark mass, mud \sim 3 MeV on an L \sim 1.8 fm lattice. We extract the pion mass = 99(4) MeV, from which we attempt a chiral "interpolation" of the observables to the physical point.

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JLQCD Collaboration, H. Fukaya, S. Aoki, S. Hashimoto, T. Kaneko, H. Matsufuru, J. Noaki, T. Onogi, N. Yamada. 2011-11-02. Chiral interpolation in a finite volume. https://arxiv.org/abs/1111.0417

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