0
votes
2answers
64 views

Lepton number conservation in standard model

Why is it said that in standard model lepton number is conserved? How do I know that Lepton number is an abelian charge? Why is this conservation not as sacred as electric charge conservation. How ...
5
votes
3answers
430 views

Does the Higgs field really explain mass or just reformulate it? What about charge?

The mass of a particle used to be considered a fundamental and intrinsic property of the particle; on the same level as other properties such as charge, spin, chirality/helicity. Due to the Higgs ...
4
votes
2answers
153 views

If nature exhibits symmetry, why don't up and down quarks have equal magnitude of electric charge?

I always hear people saying symmetry is beautiful, nature is symmetric intrinsically, physics and math show the inherent symmetry in nature et cetera, et cetera. Today I learned that half of the ...
5
votes
4answers
862 views

If the quarks in a neutron are (up,down,down), why isn't it negatively charged?

If the quarks in a neutron are (up,down,down), why isn't it negatively charged? Excuse the silly question, just wondering.
5
votes
1answer
635 views

Why do quarks have a fractional charge?

I am aware that evidence exists that strongly suggests the existence of quarks and do not doubt it. It is just simply really weird to me that they can have a fractional charge. While other ...
0
votes
1answer
170 views

Notation for Standard Model Charges?

Does anybody know what these following numbers describing an electron $(1, 1, -1)$ represent in $SU(3) \times SU(2) \times U(1)$? Or, these numbers that describe an up quark: $(3, 1, 2/3)$? I'm ...
6
votes
2answers
277 views

How quark electric charge directly have been measured?

How quarks electric charge directly have been measured when quarks never directly observed in isolation? (Due to a phenomenon known as color confinement.)
6
votes
1answer
593 views

Origin of electric charge

Baryons have charges that are the result of a polynomial calculation of their building blocks (quarks)'s fractional charges. But what gives these quarks electric charges? What interactions do they ...
7
votes
2answers
384 views

What's the deepest reason why QCD bound states have integer charge?

What's the deepest reason why QCD bound states have integer electric charge, i.e. equal to an integer times the electron charge? Given that the quarks have the fractional electric charges they do, ...
17
votes
5answers
5k 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 ...