Other Interactions
Here is a summary of a couple of the more common interactions
Annihilation
| When a particle and antiparticle collide head on they may annihilate each other and produce a pair of gamma photons |
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Creation
Two gamma photons colliding and forming a particle anti-particle pair is possible but vary rare. For a start they would have to have enough energy to convert into the mass required to create these particles ( about 1.1 MeV between them )
| A single gamma photon with sufficient energy could create a particle anti-particle pair but there are problems with this japanning because momentum must be conserved, unless it occurs in the vicinity of a nucleus. |
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Scientists who want to discover what matter consists of make these creation events occur using particle accelerators. From studying the paths of the particles created as they move in magnetic fields (i.e. the radius of their curved paths) their mass and charge can be determined. One way of doing this is to use a bubble chamber, in which the particles ionise hydrogen atoms leaving a detectable trail.
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Particles with straight paths are uncharged
The smaller the radius the bigger the acceleration so these are lighter particles, like leptons Large radius paths are heavy particles like mesons The paths spiral as the particles lose energy two opposite spirals is a particle anti-particle creation event. |
