Particle Collision: Example & Kinetic Energy

[samckx]

Hello,

Is there an example in nature of two particles with only an attractive force between them directly colliding? If so, where does the kinetic energy go?

Sam

 

[Bob S]

Fermilab collides protons with antiprotons (opposite charge, attractive-Coulomb-force particles), and lots of extra particles emerge from the collision point. The kinetic energy of the collision (≈980 GeV per incident particle) is about 1000 times greater than the rest-mass energy (≈0.938 GeV). See

http://www.fnal.gov/pub/inquiring/physics/collider/index.html

Bob S

 

[samckx]

Bob,

Thank you for the reply. Do you know if there are other examples in addition to this one? I am curious if this is this example is unique or if there are a range of examples of this type of collision.

Sam

 

[Bob S]

The Fermilab Tevatron is the best example (see my previous post) I can think of that has two mutually attractive particles colliding. Three other examples are:

The former LEP (Large Electron Positron) accelerator at CERN colliding electrons and positrons at about 50 GeV per particle.

The former proton anti-proton collider (SPS, Super Proton Synchrotron) at CERN colliding protons and anti-protons at about 300 GeV per particle.

There was also an electron-proton collider at DESY (in Hamburg Germany).

There may be other particle colliders...

Bob S

 

[samckx]

Bob,

Thanks. That gives me a good perspective.

This is a bit of different question, but do you know what physicist theorized about such collisions before there were particle accelerators? I assume they must have considered the possibility.


Sam

 

[Bob S]

The first physicist that talked seriously about building a machine for electron-positron collisions (I think) was Burt Richter at Stanford in the mid 1950's (at the Mark III electron accelerator). I now recall that electron-positron collisions were done at the joint MIT-Harvard CEA (Cambridge Electron Accelerator) about 1970.

Theorists? ... I don't know.

Bob S