强力
β\betaβ衰变的能量损失 π→μ+ν\pi\rightarrow\mu+\nuπ→μ+ν μ→e+2ν\mu\rightarrow e+2\nuμ→e+2ν νˉ+p+→n+e+\bar{\nu}+p^{+}\rightarrow n+e^{+}νˉ+p+→n+e+ 轻子数
组成规则: