单词down quark
网络: 下夸克；d夸克
In our universe, the down quark is about twice as heavy as the up quark, resulting in neutrons that are 0. 1 percent heavier than protons.
在我们的宇宙中，底夸克的质量大约是顶夸克的两倍，造成中子比质子重大约0.