Neutron ?

1. Jan 26, 2010

cragar

This might be a dumb question but can neutrons emit photons.

2. Jan 26, 2010

fatra2

Hi there,

Don't know if this is what you are looking for but: neutrons (free) are unstable particles. They will decay after a certain time into a proton emitting a beta particle. To my knowledge, there are no electromagnetic photons emitted from this disintegration though.

Cheers

3. Jan 26, 2010

cragar

what about when a neutron and an anti-neutron collide and then photons are emitted.
And lets say I had a ball oh neutrons and I heated them with a torch or had them in the presence of an alternating magnetic field , what about a neutron star.

Last edited: Jan 26, 2010
4. Jan 26, 2010

fatra2

Hi there,

Oh boy. The collision of matter and anti-matter is not consider photon emission by the particle itself. The particle anhilate and emit energy through this process.

If you want, the disintegration by a beta particle is always accompanied by the emission of a neutrino type particle. This neutrino will carry some of the energy of the disintegration. But then again, the neutrino is not a electromagnetic photon (unless considering the duality principle).

Cheers

5. Jan 27, 2010

cragar

well if the neutron has a magnetic field , then is it possible to excite this field to emit a photon ?

6. Jan 27, 2010

DarioC

7. Jan 27, 2010

cragar

thanks

8. Jan 27, 2010

likephysics

Neutron has no charge, so no mag field.

9. Jan 27, 2010

cragar

Then how do you explain the neutron magnetic moment . A neutron posses spin and anything with spin has a magnetic moment .

10. Jan 28, 2010

likephysics

I did not know that. I thought motion of electric charge produced mag field. Thanks.

11. Jan 28, 2010

cragar

Its ok , I think that neutrons can emit photons because they are made of quarks and like protons that emit light fairly easily . I am not 100% sure.

12. Jan 28, 2010

Claude Bile

To a first (classical) approximation, no; EM waves are produced by oscillating charges and since neutrons possess no net charge, they do not emit EM waves.

Claude.

13. Jan 28, 2010

cragar

It just seems that if i heat up a nuetron really hot it would emit something ,
so a neutron can have an EM field but not emit photons.

14. Jan 29, 2010

vanesch

Staff Emeritus
I was hesitating to jump in because it's a bit a tricky issue. As the neutron has a magnetic moment, it thus can interact through the electromagnetic field, and as such, one should say that it can "emit (virtual) photons" ; that is, you can link a neutron in a Feynman diagram with a photon, although this is somewhat messy as it isn't directly charged.

However, if you mean real photons, such as emissions of gamma radiation, then no. Of course, you can think of the quarks inside the neutron as a bound state, and think of exciting those. But then it is not a neutron anymore ! The neutron is a bound state of down-down-up. There exist other such states, for instance the Delta-0 particle. You could consider it as an "excited" neutron state if you which. See for instance the Wiki article on it:
http://en.wikipedia.org/wiki/Isospin

You see the neutron in the left-upper corner of the baryon octet spin-1/2 and the Delta-0 baryon second from the left in the upper row of the baryon decuplet spin-3/2.

15. Jan 29, 2010

cragar

Interesting , thanks for the responses i learned a lot in this thread .