A quantum property of the charm quark whose conservation explains the absence of certain strange - particle decay modes and that accounts for the longevity of the J particle.

• 分子量夸克粒子的一种量子属性，夸克粒子的存在说明了某些特别粒子腐蚀模式的缺乏，这也是J粒子存在时间长的原因