All Questions
Tagged with standard-model weak-interaction
152
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What is the associated charge for the weak neutral current?
So for the strong force, there's color charge; for electromagnetism, there's electric charge; and for weak charged current, there's weak isospin. How about the weak neutral current? Is there an ...
-1
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2
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77
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How can a virtual $W$ boson turn into an electron and electron antineutrino?
This is specifically with regard to beta decay. My current understanding is that in one type of beta decay, a neutron turns into a proton, an electron, and an electron antineutrino. In order to change ...
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1
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132
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Kinematics in the pion decay
If a charged pion decays via a charged current $W$, the $W$ boson is much heavier than the pions. How is this not a problem? Could the processes be off-shell in such a drastic manner?
It is tempting ...
- 126
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Does the kaon participate in the weak interaction?
I'm looking at a physics textbook for A-level and in the book it states that kaons are only affected by the strong force and the electromagnetic force.
Isn't this incorrect?
Aren't kaons affected by ...
- 109
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55
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Do the WI coupling constants change sign under $C$?
I am trying to understand discrete symmetries in the SM, and I have some troubles in understanding why the CC interaction violates CP. In my (badly written) notes it's said that, taken two fermonic ...
- 475
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65
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Feynmann diagram for $W$ boson decay
So a $W^{-}$ boson decays into right-handed antineutrino and left-handed lepton with "wrong" helicity. I found that textbook explanation of that process involves lots of handwaving.
I am ...
- 203
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50
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Why is the fermionic sector of Standard Model the way it is? [closed]
"Because it works!" will be considered too broad an answer. I want to precisely know which experiments forced to consider the model construction the way it is. For example, I can see Wu's ...
- 785
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81
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Why is the vacuum state $|0\rangle$ invariant under parity?
I was studying the leptonic pion decay $\pi\rightarrow l\nu_{l}$, and usually the amplitude is computed by
$$\mathcal{M}(\pi\rightarrow l\nu_{l})=-i\frac{G_{F}}{\sqrt{2}}V^{*}_{ud}\langle0|\bar{d}\...
- 475
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69
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How Fast Can Toponium Form?
I understand that Toponium is only theoretical because the T quark decays too quickly.
My question is this, would a right handed T quark live long enough to form a meson? If not, how long would it ...
- 2,706
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Is this Why a Neutron can Decay Into a Proton, Electron and Electron Antineutrino?
A neutron is udd, then an u-anti-u starts to exist close to the neutron. Then the one d and u change places forming an uud (proton) and anti-ud which decays to an electron and electron-antineutrino. ...
-2
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1
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52
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Isn't weak interactions necessarily violate strangeness?
The electron-proton elastic scattering process $$e^-+p^+\to e^-+p^+$$ can take place either via a photon exchange (electromagnetic interaction) or via $Z^0$ exchange (weak interaction). But isn't weak ...
- 11.8k
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109
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How is this equation about pion decay derived?
I'm reading Peskin's Concepts of Elementary Particle Physics and these equations confuse me.
What are the $\pi^1$ and $\pi^2$ in (15.49) and why $\pi^-$ equals to this?
I don't understand the ...
- 43
1
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1
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77
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How do we prove that hypercharge is different for singlets and doublets?
I am trying to teach myself about the standard model and I am stumped by this point.
I understand that:
When picking an U(1) generator for SU(2)xU(1), any multiple of the identity will do ($YI_n$)
...
- 53
-2
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104
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Why is $\beta$ decay a weak force interaction?
In my graduation and also in post graduation, I was told that $\beta$ decay is a weak interaction. But till date I don't know the reason as if why it is a weak interaction process. In my classes some ...
2
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1
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111
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Why were weak neutral currents considered evidence for electroweak theory?
For example, Wikipedia says:
The existence of the electroweak interactions was experimentally established in two stages, the first being the discovery of neutral currents in neutrino scattering by ...
- 6,601