Study of resonance state from lattice QCD

本项目的目的之一是建立一种从格点QCD研究共振态性质的方法。ρ介子衰变是朝着这个目标进行研究的。数值计算是在两个夸克质量下进行的，对应于π介子质量m= 410MeV和300MeV。根据每次计算得到的有效ρππ耦合常数估算了物理点（m=140MeV）处的衰变宽度。结果表明，衰变宽度分别为130（18）MeV和152（28）MeV，与146MeV的实验值一致。这意味着本项目中的方法是研究共振状态的可靠和有效的方法。这种方法的应用，许多其他的共振，预计在未来

An aim of this project is to establish a method for an investigation of properties of a resonance state from the lattice QCD. The rho meson decay is studied toward this aim. The numerical calculations were carried at two quark masses which correspond to the pion mass m=41OMeV and300MeV. The decay width at the physical point(m=140MeV)is estimated from the effectiveρππcoupling constant obtained from each calculation. The results of the decay width are130(18)MeV and152(28)MeV, which are consistent with the experiment146MeV. This means that the method in this project is a reliable and an efficient method for a study of the resonance state. Applications of this method to many other resonances are expected in the future