3
votes
1answer
59 views

How can a left-handed fermion field create a right-handed antifermion?

My question - which is likely stupid or appears due to some confusion - stems from the following considerations: when quantizing canonically we are told (see any book on QFT) that a Dirac fermion ...
1
vote
0answers
114 views

Fermi theory of beta decay

What are the facts that one should consider and incorporate in going from non-relativistic Fermi theory of beta decay to its relativistic generalization? In other words, how would the Lagrangian or ...
0
votes
3answers
81 views

Exchange Particle between an Electron Neutrino and Neutron?

How can a neutrino turn a neutron into a proton? This is the equation, $$ \nu_e + n \to p + e^- \,.$$ If you draw the Feynnmann Diagram which I attempted here, "Diagram" there isn't an exchange that ...
1
vote
1answer
59 views

Allowed interactions for the neutral weak vector boson

Just wanted to double check a couple of things for my own sanity! I am looking at scattering amplitudes for 2 partons going to two partons with the emission of a Z boson (eventually decaying to e+ ...
8
votes
2answers
1k views

Weak force: attractive or repulsive?

We are always told that there are the four fundamental forces or interactions of nature: gravitation, electromagnetism, and the weak and strong forces. We know that gravitation is attractive, that ...
0
votes
0answers
47 views

chirality oscillations in weak interaction

As far as I have understood, the mass $m$ of a fermion causes a coupling of the both chiralities $\psi_L$ and $\psi_R$. This coupling would induce an oscillation of the chirality within a time scale ...
4
votes
1answer
354 views

What is the formal definition of spin-independent vs. spin-dependent scattering?

In the search for WIMPs as the dark matter particle, there is an important distinction between spin-independent and spin-dependent scattering. Roughly, WIMPs scattering from nucleons through a ...
1
vote
3answers
264 views

Effective operator in four-fermion interaction

In one book, I have got the following lines which I found myself unable to understand what is effective operator? The paragraph is given below: The weak interaction describes nuclear beta decay, ...
0
votes
0answers
105 views

What would the universe be like if Electroweak symmetry were unbroken? [duplicate]

Possible Duplicate: What happens to matter in a standard model with zero Higgs VEV? What if the Higgs did not have a "Mexican hat" potential and the therefore it's vacuum expectation value ...
7
votes
3answers
955 views

Why does the weak force distinguish left and right handedness?

I'm wondering why the weak interaction only affects left-handed particles (and right-handed antiparticles). Before someone says "because thats just the way nature is" :-), let me explain what I find ...