Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Consider two bare protons. One (A) is stationary (relative to some arbitrary massless observer); the other (B) is approaching A at 1 m/s. When they collide, I assume that they bounce.

What is the precise mechanism by which energy is transferred from A to B?

For bonus points: Is the mechanism the same if each proton has one electron (that is, a normal hydrogen atom)?

share|cite|improve this question
I don't know if relevant to this particular scattering, but a normal hydrogen atom has one neutron too ;) – Jorge Jan 26 '13 at 9:29
@Nivalth: The normal deuterium atom has one neutron, but the normal hydrogen atom doesn't. – John Rennie Jan 26 '13 at 9:58

You are asking for the whole theory of scattering developed the past 80 years.

Please have a look at this lecture which covers proton proton scattering.

In a nutshell, any scattering transfers momentum and energy between target and incoming with the exchange of a virtual gauge boson and possibly other allowed by quantum numbers particles. A virtual particle exchange.

A scattering of hydrogen on hydrogen involves only the electromagnetic exchanges, i.e. virtual photons.

share|cite|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.