j/psi particle

美

英

英英

n.	1. an unstable elementary particle of the meson group. It has a large mass, about 6,000 times that of an electron, and is thought to be formed from charmed quarks.

随便看

英汉双解词典包含2704715条英汉词条，基本涵盖了全部常用单词的翻译及用法，是英语学习的有利工具。