the half life of the uncharged pion is 6×s. 中性兀介子的半衰期为6秒。
the antiparticle of the π°is indistinguishable from the π°. 介子的反粒子同本身是无法区分的。
" for his prediction of the existence of mesons on the basis of theoretical work on nuclear forces 提出核子的介子理论并预言介子的存在
Read chap . 5 of your text book to complement our discussion of heavy mesons in chiral perturbation theory 10阅读教材第五章以补充关于手征微扰理论中重介子的讨论。
Meanwhile we find that decay constant fn and the tt mass mv monotonously decrease as nuclear matter density increases 我们同时发现介子的衰变常数f _和质量m _随着核物质密度_ n的增加而单调递减。