Protons Hog the Momentum in Neutron-Rich Nuclei https://www.jlab.org/news/releases/protons-hog-momentum-neutron-rich-nuclei
quote <<...the researchers compared the momenta of protons versus neutrons in these nuclei. According to the Pauli exclusion principle, certain like particles can't have the same momentum state. So, if you have a bunch of neutrons together, some will have low momentum, and others will have high momentum; the more neutrons you have, the more high-momentum neutrons you would see, as they fill up higher and higher momentum states. But according to Higinbotham, that expected picture is not what the researchers found when they measured high-momentum protons in neutron-rich nuclei. "What this paper is saying is the reverse, that the protons actually have the higher-average momentum. And it’s because they’ve all paired up with neutrons," Higinbotham says. "It’s like a dance with too many girls (neutrons) and only a few boys (protons). Those boys are dancing their little hearts out, because there aren’t very many of them. So the average proton momentum is going to be higher than the average neutron momentum, because it’s mostly the neutrons that are sitting there, doing nothing, with nothing to pair up with, except themselves.">> Harry
