So the name of the game is getting nuclei close enough for the strong force to take over. There is very active and promising research going on into fusion power, it’s just not cold fusion (and that’s what the question is about). We can initiate an actual, honest-to-god fusion reaction at below room temperature, which is exactly what cold fusion is supposed to be. So technically, cold fusion is not only possible, but has been done for the better part of a century. About twice as much power as you can recover from the muon-assisted cold fusion the particle cannon enables, even under ideal conditions.