1
vote
4answers
819 views

Why is Neutron Heavier than Proton?

This is Neutron decay: $$n^o \to p^+ + e^- + \overline {\nu_e}.$$ and this is proton one: $$p^+ \to n^o + e^+ + \nu_e$$ so when the $e^+ =e^-$ and $\nu_e=\overline {\nu_e}$ why $n \not= p$? my ...
1
vote
1answer
287 views

Quark Radius Upper Bound

If quarks had internal structure (contradicting current beliefs), what is the lowest upper bound on their "radius" based on current experimental results? If possible, I'd prefer to only consider ...
10
votes
4answers
2k views

Why do electron and proton have the same but opposite electric charge?

What is the explanation between equality of proton and electron charges (up to a sign)? This is connected to the gauge invariance and renormalization of charge is connected to the renormalization of ...