出典:Wiktionary
出典:Wikipedia
出典:『Wikipedia』 (2011/04/26 20:33 UTC 版)
B mesons are mesons composed of a bottom quark or bottom antiquark and either an up (B+
), down (B0
), strange (B0
s) or charm quark (B+
c). The combination of a bottom antiquark and a top quark is not thought to be possible because of the top quark's short lifetime. The combination of a bottom antiquark and a bottom quark is not a B meson, but rather bottomonium.