# Basic questions on collisions, particles

1. Jan 29, 2012

### Helicobacter

Since particles are really better described as exponentially decreasing energy amplitudes fields in a configuration space (space-time)...how close do the max energy point of a particle and the max energy point of a antiparticle have to be before they annihilate? This critical distance between the energy peaks is determined by what?

Furthermore why does a electron and positron annihilating produce two photns and not three "gummybear particles" (invented by me) with each having [MEV of postron+MEV of electron]/3 mass?

Claim: the graph on y axis: number of such atoms in the universe, on the x axis: atoms of a certain proton count (increasing)...is distributed with a shape that reminds of the distribution of the exponential family.
Is my claim true? If so, why?

im not a physics person so please keep it light.

2. Jan 29, 2012

### mathfeel

There is no such thing as a critical distance. The size of the wavefunction packets is not an intrinsic properties of eletrons/positrons, but what state they are in. And in any states, there is a finite probability that they would annihilate and turn into some other pairs (photon is not the only process, just one with relative high probability). The probability is intuitive related to how much the two packets overlap.

The basic equations of nature (known as the Lagrangian) has a term that couples a charged particle, its charged anti-particle, and two photons. At the beginning, theoretical physicists put such terms in there there because we observe particle/anit-particle annihilation into two photons. Now if someone discover (as in make an observation of) a process of annihilation into three gummybearon, then we'll be forced to put something that describe gummybearon and its interaction with electrons/positions in there.

Well, that's not the entire story. Modern physics have developed symmetry arguments why certain term describing certain field must be in the basic equations and in what form (e.g., annihilating to three photons are not allowed). So you can say that the existence of photon and how it couples to charged particle--that is, electromagnetism itself--is a consequences of the symmetries of nature.

3. Jan 29, 2012