Tagged Questions
1
vote
2answers
90 views
The status of $SU(3)_C$ symmetry in the Standard Model
In the Standard Model of Particle physics the $SU(2)_{EW}$ symmetry and the $SU(2)$ isospin symmetry are broken. What about $SU(3)_C$? Is it broken too?
if YES, what breaks the symmetry?
If NO, what ...
0
votes
0answers
101 views
Weak isospin and types of weak charge
My understanding is that QCD has three color charges that are conserved as a result of global SU(3) invariance. What about SU(2) weak? Does it have two types of charges? What I'm getting at is:
U(1) ...
5
votes
2answers
116 views
Why is there a linear relationship between charge and isospin?
So the title basically says it all. Something that's really bothering me is the fact that the Gell-Mann Nishijima relationship can be extended to provide a linear relationship between charge and all ...
5
votes
2answers
97 views
What maintains quark spin alignments in baryons?
What maintains quark spin alignments in baryons?
The $uud$ proton and $udd$ neutron are both spin 1/2, implying that two of their spin 1/2 quarks are always parallel and the other is always opposed.
...
3
votes
2answers
104 views
Playground of Forces
Why is it that the gravitational force acts on large sized objects while the strong and weak nuclear forces act at subatomic levels only? What is that stops each other to enter each others domain?
3
votes
2answers
139 views
Simulating a proton
How much computing power would it take to simulate a single proton from the bottom up, without taking any shortcuts whatsoever?
My current understanding is that:
A proton is basically a seething ...
4
votes
3answers
229 views
Do strong and weak interactions have classical force fields as their limits?
Electromagnetic interaction has classical electromagnetism as its classical limit. Is it possible to similarly describe strong and weak interactions classically?
3
votes
1answer
233 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, ...
-6
votes
2answers
245 views
Cramer's rule, Origin of Quarks Fractional electric charge? [closed]
In linear algebra, Cramer's rule is an explicit formula for the solution of a system of linear equations with as many equations as unknowns.
2u+1d=1
1u+2d=0
$$a_1d+b_1u=c_1$$ $$a_2d+b_2u=c_2$$ ...
-4
votes
1answer
228 views
Pion Decay and Fractional electric Charge disappeared, why?
Since the charged pions decay into two particles, a muon and a muon neutrino Fractional electric Charge disappeared, why?
The decay proceeds by the weak interaction $W^{+}$ and can be visualized in ...
-7
votes
2answers
435 views
Could the fractional model of Quarks electric charge turn out to be false? [closed]
The delta baryons (also called delta resonances) are a family of subatomic hadron particles which have the symbols $\Delta^{++}$, $\Delta^{+}$, $\Delta^{0}$, and $\Delta^{−}$ and electric charges +2, ...
6
votes
2answers
209 views
Is there an explanation for the 3:2:1 ratio between the electron, up and down quark electric charges?
I understand that the NNG formula relates $Q$, $I_3$, and $Y$ and can be derived in QCD; does this unambiguously predict the electric charge ratios without making assumptions about the definitions of ...
2
votes
1answer
130 views
Similar masses and lifetimes of the $\Delta$ baryons
Why do the four spin 3/2 $\Delta$ baryons have nearly identical masses and lifetimes despite their very different $u$ and $d$ quark compositions?
