著者

Feng Xu Aoki Sinya Fukaya Hidenori Hashimoto Shoji Kaneko Takashi Noaki Jun-ichi Shintani Eigo JLQCD Collaboration

出版者

American Physical Society

雑誌

Physical Review Letters (ISSN:00319007)

巻号頁・発行日

vol.109, no.18, pp.182001, 2012-11

被引用文献数

20 8

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We perform a nonperturbative calculation of the π0→γγ transition form factor and the associated decay width using lattice QCD. The amplitude for a two-photon final state, which is not an eigenstate of QCD, is extracted through a Euclidean time integral of the relevant three-point function. We utilize the all-to-all quark propagator technique to carry out this integration as well as to include the disconnected quark diagram contributions. The overlap fermion formulation is employed on the lattice to ensure exact chiral symmetry on the lattice. After examining various sources of systematic effects, except for a possible discretization effect, we obtain Γπ0→γγ=7.83(31)(49)  eV for the pion decay width, where the first error is statistical and the second is our estimate of the systematic error.