# Particle collision/interaction

1. Apr 21, 2010

Within the atom can particle interaction cause an exchange affecting the fermions spin/charge without invoking structural change in the fermions? If so could the eV temporarily change if the spin is affected?
Thanks TM

2. Apr 21, 2010

### ansgar

which fermions? the neutrons? protons? electrons?

there is at least spin coupling within the atom, the so called Lamb Shift

http://en.wikipedia.org/wiki/Lamb_shift

you should try to have better titles for your questions in the future

3. Apr 21, 2010

The lamb shift in this article is describing the influence on the electron, the electron is a fermion but this is a fermion boson interaction. This is not a collision/interaction between fermions. I want to know fermion fermion interaction. The fermions in protons and neutrons are up quarks and down quarks. is there any exchange/influence occurring between fermions?
Thanks TM

4. Apr 21, 2010

### ansgar

no it is a fermion - fermion interaction mediated with a boson (the photon)

are u wondering if there are fermions which carry "force"?

5. Apr 21, 2010

If so what two fermions are interacting in this formula, the electron is one fermion where is the other? W and Z bosons have a Mass so the force that acts on the fermions from the elec and magnetic field is the W boson because it carries a different charge to the y,g,z so the affect is the W boson cannot occupy the same quantum state. Fermions can create fields but are not apart of the field.

6. Apr 21, 2010

Please correct me if im wrong

7. Apr 21, 2010

### ansgar

the electron before the photon "hits" it (of course this photon will be virtual in the lamb shift) then after the "interaction" there is one electron, but with spin changed.

8. Apr 21, 2010

If a photon has zero charge and zero mass how does it “collide” with the electron? I know of electrons emitting photons. They possess chromo dynamic energy but no charge so where does this collision occur. If I throw a ball through a hoop and it doesn’t touch the sides, its not a collision. But if I throw it so fast it was to act upon the hoop as it passed through this is still not a collision. The force/energy transferred to the hoop was because of the ball affecting the wind pressure not the hoop directly.
To sum this up the photon is not the force medium between the boson fermion interaction in the field. It is the W and Z bosons. But what I want to know is fermion-fermion interactions.
Is there an influence to a fermion if a different fermion or the same type of fermion was to pass very close to affect the state of the fermion but not change the structure its apart of? Can there be fluctuations in mass due to this interaction?

9. Apr 21, 2010

### ansgar

no they do not possess chromodynamic energy...

NO elementary particle "collides" as two balls colliding, elementary particles have no size at all.

where did u learn particle physics?

10. Apr 21, 2010