Are photons affected by the strong force? The weak force?

I'm inclined to believe that photons, being the electromagnetic force carriers, aren't affected by any other forces. but then, this is not really my field. haha, excuse the pun.

 

Many nuclei have photonuclear reactions, such as (photon,neutron) or (photon, alpha particle). For example, photons above about 20 MeV on oxygen-16 will knock a neutron out, leaving radioactive oxygen-15. The cross section is typically a few millibarns.
For comparison, the nuclear size (radius) for oxygen is about R=1.3A^1/3 x 10^-13 cm = 3.2 x 10^-13 cm, so geometric area = 0.33 barns.

 

Yeah, but that's an electromagnetic interaction. Photons are not affected by the strong force.

I think they would be affected by the weak force, since the W bosons (carriers of the weak force) are charged. I don't know enough offhand to describe that in detail, though.

 

if the energy levels were high enough the electromagnetic and weak forces would unify, so it wouldn't be surprising if, in those conditions, and photon could conceivably be affected by the... well not really weak force, rather the elctroweak force

 

Photons will not interact with those at these energy scales though, this is why one needs electroweak unification at very very high energies.

 

photoelectric effect is not a atomic reaction, but a reaction in a solid where the electrons behaves as a collective.

Here are some resources

http://www.ndt-ed.org/EducationResources/CommunityCollege/RadiationSafety/theory/interaction.htm

http://www.sciencemadness.org/lanl1_a/lib-www/la-pubs/00326397.pdf

 

Of course it can. Can you see through glass?

 

i) In QM, photons do not go straight lines, we don't have defined paths in quantum mechanics. Particles are not tiny tiny balls, and the atom is not a tiny tiny solar system. Photons do not "travel through atoms"

ii) Interactions and processes are deterministic, the photon has a certain probability to interact with the atom/electron/nucleus. The probability is a function of energy and material etc.

iii) Interactions in matter is not atomic feature but solid, the electronsm behave as collective -> constituting a energy band (in atom we have energy levels/lines)

What you are asking doesn't make sense in a QM point of view. In QM sense we have two basic ingredients: 1) probability of outcome 2) energy bands

Glass have an energy band in the optic spectra, wheras some other material don't.

 

yes QM, but in QM we don't have particles traveling around like tiny balls...

 

i just told you the basics, the photon has a probability to interact with matter as a function of its energy.

 

Photons can knock an electron out of a single atom of gas, with the only final state components being a photoelectron, and a recoil ionized atom. One example would be a 15-eV UV photon ionizing a gaseus hydrogen atom, with a photoelectron and a recoil proton in the final state.

 

Can light travel through an atom? If yes, how will it emerge? If no, why not? Will it interact with any subatomic particles?

Good question. Simple questions often have no simple answers. This is one. One could possibly write a book in reply. If you are looking for a purely quantum mechanical explanation read no further as I don't know theoretical QM at that level of detail. Your question is posed in classical terms but is under QM so I'm not sure if you realize the overlap between different fundamental theories. Quantum field theories for the strong nuclear force and the weak nuclear force have been developed, the former called quantum chromodynamics and might be of interest to you.

A classical analogy would be to ask "does light travel through the earth sun complex?" think of the sun as the nucleus the earth as an electron....atoms are 99% (illustrative number only) empty like this system. so usually light DOES usually pass through an atom in this sense...it passes through the "vacuum" as you posted. (but it is NOT a vacuum). And the phton NEVER goes exactly STRAIGHT through because each photon IS deflected every so slightly by gravity...say of the nucleus, but that's not measureable.

Another reasonable answer is that photons interact with materials (atoms) in a number of different ways which depends both on the energy of the photon and the nature of the material. Some materials reflect most light , others are translucent like glass (pass most light) yet can also "bend" (focus) light like a concave glass lense, other materials are opaque and others exhibit the photo electric effect. Each affects light (photons) a bit differently.
In quantum mechanics, since a photon is likely to bring an atom into a firm state if it wasn't already ( collapsing the wave function in one interpretation) likely the photon can't "travel through" in the classical sense, but the actual result as noted by others is statistical in nature.

The strong force affects quarks, the weak force radioactive decay, the electromagnetic force charged particles; a photon is none of these but IS affected by the gravitational force. See gravitational lensing which CAN be measured.

You can also look up COMPTON SCATTERING in wikipedia, for example, for related interactions...and note the wave particle duality....

 

But that we call Ionizing ;-)

 

In some (most) physics books, photon scattering off an electron (with a photon in final state) is called Compton scattering, and photoelectric when there is no secondary photon. Accelerator builders are now acceleratiing H-minus beams; a single proton with two electrons. The H-minus atom has charge of minus one. A 2-eV photon (red laser) can knock off one electron, leaving a photoelectron and a neutral hydrogen atom. Would you call this a de-ionizing reaction? See
http://neutrons.ornl.gov/aboutsns/how_sns_work.shtml [Broken]

 

What is the difference of photoelectric effect and ionization then?