> Han nation
Since many years ago, China Daily or even Beijing Review (two English publications published by Chinese) used the word nationality to mean 族, so shaoshu minzu is minority nationality, and so on. I don't think that's correct. "Nationality" means citizenship as in:
A: What's your nationality?
族 in Chinese is rather ethnicity or race. So I would say "the Han ethnic group" is a good answer to your question.