Running coupling constant of ten-flavor QCD with the Schr\"odinger functional method

Walking technicolor theory attempts to realize electroweak symmetry breaking as the spontaneous chiral symmetry breakdown caused by the gauge dynamics with slowly varying gauge coupling constant and large mass anomalous dimension. Many-flavor QCD is one of the candidates owning these features. We focus on the SU(3) gauge theory with ten flavors of massless fermions in the fundamental representation, and compute the gauge coupling constant in the Schr\"odinger functional scheme. Numerical simulation is performed with $O(a)$-unimproved lattice action, and the continuum limit is taken in linear in lattice spacing. We observe evidence that this theory possesses an infrared fixed point.Comment: 28 pages, 6 figures. v2) remarks on the continuum limit added, analysis simplified and done with more statistics, conclusion unchanged, version accepted for publication in PR

Effect on water mass structure in West Japan by the 2011 Tohoku earthquake tsunami

The 2011 Tohoku earthquake tsunami devastated the coastal zone in east Japan. It was also reached to the Pacific coast in west Japan area. The most reports have been limited reaching time and height of tsunami. However, it is important to consider the effect on water mass structure by tsunami waves from the viewpoint of sustainable fisheries industry or conservation of marine ecosystem. In this study, from the analysis for monitoring data in Shikoku and Seto Inland Sea, temporal breaking the stratification and the appearance of high-frequency component were confirmed

Electromagnetic mass splittings of the low lying hadrons and quark masses from 2+1 flavor lattice QCD+QED

Results are presented for the electromagnetic mass splittings of the low lying hadrons. These are used to determine the non-degenerate light quark masses. It is found that m_u=2.24(10)(34), m_d=4.65(15)(32), and $m_s=97.6(2.9)(5.5)$ MeV (MSbar scheme, 2 GeV scale). The first error is statistical and the second systematic. We find the lowest order electromagnetic splitting (m_pi+-m_pi0)_QED=3.38(23) MeV, the splittings including next-to-leading order, (m_pi+-m_pi0)_QED=4.50(23) MeV, (m_K+-m_K0)_QED=1.87(10) MeV, and the m_u != m_d contribution to the kaon mass difference, (m_K+-m_K0)_(m_u-m_d)=-5.840(96) MeV. All errors are statistical only, and the next-to-leading order pion splitting is only approximate; it does not contain all next-to-leading order contributions. We also computed the proton-neutron mass difference, including for the first time, QED interactions in a realistic 2+1 flavor calculation. We find $(m_p-m_n)_{\rm QED}=0.383(68)$ MeV, (m_p-m_n)_(m_u-m_d)=-2.51(14) MeV, and the total m_p-m_n=-2.13(16)(70) MeV, where the first error is statistical, and the second, part of the systematic error. We use domain wall fermions and the Iwasaki gauge action (gauge coupling beta=2.13). We use two lattice sizes, 16^3 and 24^3, to address finite volume effects. Non-compact QED is treated in the quenched approximation. We present new results for the electromagnetic low energy constants in SU(3) and SU(2) partially-quenched chiral perturbation theory to the next-to-leading order, obtained from fits to our data. Detailed analysis of systematic errors in our results and methods for improving them are discussed. Finally, new analytic results for SU(2)_L x SU(2)_R-plus-kaon chiral perturbation theory, including the one-loop logs proportional to alpha_em*m, are given.Comment: Significant additions: finite volume analysis of kaon mass (Sec. II and the Appendix) which is used to obtain new central values, extended discussion of the breaking of Dashen's theorem (VII), additional phenomenological results (VII), and a new section (VIII) on isospin breaking effects on the kaon decay constant. No conclusions or results from the first version changed significantl