[填空题]
If the mass of the pa0f,)-s aowy froton were just a little closer to the milp.yac0of3;j bsw 8( ass of the neutron, the fol3fj.s(y aol8;ic w0 bplowing reaction would be possible even at low collision energies:
$\text{e}^- + \text{p} \to \text{n} + \nu$.
Why would this situation be catastrophic? By what percentage would the proton's mass have to be increased to make this reaction possible? $\frac{KE_{\alpha}}{KE_{\beta}}$ = $\frac{ \times 10^{-4}}{1}$
