The main composition of the universe is HYDROGEN. But are the protons in the center of the star and the protons in the surface layer of the star the same as ordinary protons?
There are also several unsolved mysteries about protons.
This paper is based on the results of Seaquest(2021) of Fermilab in America. The relationship between mu²+mu²=md² and three valence quarks in proton is deduced.
The sum of squares of the upper quark mass is equal to the square of the lower quark mass. The valence quarks of other baryons do not have this phenomenon.

The relationship between three valence quarks in proton is a new discovery after Standard Model theory and QCD theory. From mu²+mu²=md², it can be inferred that there are three generations of protons in the universe. The cause of the expansion of the universe, why are protons stable? The problem of proton spin can be explained reasonably.

This paper deals with the basic problems of particle physics and astronomy. I hope that all scholars will give valuable opinions on this article. The development of science needs our joint cooperation. Since I can't see the comments on ScienceOpen, please contact me by (Email).

jianming wang        (china)                            Email: wsr529@sina.com