arXiv subjects

Hidenori Fukaya

Publications and source records attributed to Hidenori Fukaya.

95 records · Page 6Linked to original sources

arXiv2004

Anisotropic lattice with nonperturbative accuracy

We determine the nonperturbative anisotropic parameter of the gauge action in the quenched approximation with less than 1% accuracy using the Sommer scale measured by the Lüscher-Weisz algorithm or smearing technique. We also study the nonperturbative O(a)-improvement of the quark action. The bare quark anisotropy is determined using the masses from the temporal and spatial directions. For the determination of the $O(a)$ improvement coefficients, we apply the Schrödinger functional method.

hep-lat↗

arXiv2004

Theta vacuum effects on the pseudoscalar condensates and the eta^prime meson in 2-dimensional lattice QED

We study the chiral condensates and the eta^prime meson correlators of the massive Schwinger model in non-zero theta vacuum. Our data suggest that the pseudoscalar operator does condense in a fixed topological sector and gives long range correlations of the eta^prime meson. We find that this is well understood from the clustering decomposition and statistical picture. Our result also indicates that even in theta=0 case, the long range correlation of eta^prime meson receives non-zero contributions from all the topological sectors and that their cancellation is non-trivial and requires accurate measurement of the reweighting factors as well as the expectation values. It is then clear that the fluctuation of the disconnected diagram originates from the pseudoscalar condensates.

hep-lat↗

arXiv2004

Theta vacuum effects on the chiral condensation and the eta^prime meson correlators in the two-flavor massive QED_2 on the lattice

We study the scalar and pseudoscalar condensations and the eta^prime meson correlators of the two-flavor massive Schwinger model in the non-zero theta vacuum. Exploiting our new method which was developed to investigate topological effects in the previous work, we find that the pseudoscalar condensation is non-zero and there exists a long-range correlation of the eta^prime meson. This phenomenon is well described by the clustering property. We also find that even in theta=0 case the cancellation of the long-range correlation is nontrivial and requires accurate contributions from higher topological sectors. Our results imply that the fluctuation of the ``disconnected'' diagram originates from the pseudoscalar condensation in each topological sector.

hep-lat↗

arXiv2003

Lattice Study of the Massive Schwinger Model with a $θ$ term under Lüscher's "Admissibility" condition

We present a numerical study of the massive two-flavor QED in two dimensions with the gauge action proposed by Lüscher, which allows only ``admissible'' gauge fields. We find that the admissibility condition does not allow any topology changes by the local updation in Hybrid Monte Carlo algorithm so that the configurations in each topological sector can be generated separately. By developing a new method to sum over different topological sectors, we investigate $θ$ vacuum effects. Combining with domain-wall fermion action, we obtain the fermion mass dependence and $θ$ dependence of the meson masses, which are consistent with the analytic results by mass perturbation in the continuum theory.

hep-lat↗

arXiv2003

Lattice Study of the Massive Schwinger Model with $θ$ Term under Lüscher's "Admissibility" Condition

Lüscher's ``admissibility'' condition on the gauge field space plays an essential role in constructing lattice gauge theories which has exact chiral symmetries. We apply the gauge action proposed by Lüscher with the domain-wall fermion action to the numerical simulation of the massive Schwinger model. We find this action can generate configurations in each topological sector separately without any topology changes. By developing a new method to sum over different topological sectors, we calculate meson masses in nonzero-$θ$ vacuum.

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