I understand that mass can be created from energy, this follows the equation $E= mc^2$, but can nucleons be created?
If I gave you a number of nucleons in whatever form you'd like and as much energy as you'd like, is there a way for you to give me back more nucleons then I originally gave you?
The reason this question occured to me is because it is my understanding that in a star hydrogen is turned to helium (and sometimes heavier elements) and that releases energy but at no point does the total number of nucleons change. Neutrons can turn into protons and vice versa but the total number of neutrons and protons does not change during any of these reactions.
If any of this is incorrect please correct me.
In general, is there a way to create or destroy nucleons?