@article{oai:tsukuba.repo.nii.ac.jp:00049233,
 author = {吉江, 友照 and YOSHIE, Tomoteru and Ishizuka, N. and Ishikawa, K.-I. and Ukawa, A.},
 issue = {11},
 journal = {Physical review D},
 month = {Dec},
 note = {We present our result for the K→ππ decay amplitudes for both the ΔI=1/2 and 3/2 processes with the improved Wilson fermion action. In order to realize the physical kinematics, where the pions in the final state have finite momenta, we consider the decay process K(p)→π(p)+π(0) in the nonzero momentum frame with momentum p=(0,0,2π/L) on the lattice. Our calculations are carried out with Nf=2+1 gauge configurations generated with the Iwasaki gauge action and nonperturbatively O(a)-improved Wilson fermion action at a=0.091??fm (1/a=2.176??GeV), mπ=260??MeV, and mK=570??MeV on a 483×64 (La=4.4??fm) lattice. For these parameters the energy of the K meson is set at that of two-pion in the final state. We obtain ReA2=2.431(19)×10?8??GeV, ReA0=51(28)×10?8??GeV, and ε′/ε=1.9(5.7)×10?3 for a matching scale q?=1/a where the errors are statistical. The dependence on the matching scale q? of these values is weak. The systematic error arising from the renormalization factors is expected to be around 1.3% for ReA2 and 11% for ReA0. Prospects toward calculations with the physical quark mass are discussed.},
 title = {Calculation of K→ππ decay amplitudes with an improved Wilson fermion action in a nonzero momentum frame in lattice QCD},
 volume = {98},
 year = {2018},
 yomi = {ヨシエ, トモテル}
}