Spinnor said:How big is the box you put them in? The more room the particles have to roam the smaller the chance they will "meet".
frogjg2003 said:I'm getting 3.22 instead of 3.28. If you're posting because your answer is wrong, that might be why. Try using more digits in your calculations.
I'm also guessing that you aren't supposed to consider that the electron and positron have kinetic energy as well as mass energy, otherwise you would have to take that into account, but no information has been given to you.
ZedCar said:...
The reason I ask is because the lecturer provided on the board the following solution:
Electron pair requires at least 2mc^2=1.02MeV of energy
Δt ~ (h-bar)/ΔE
...
Spinnor said:Is there a factor of 2 missing above? Δt ~ (h-bar)/ΔE
An electron-positron pair is a subatomic particle created when an electron and a positron (the anti-particle of an electron) collide. This collision results in the creation of two particles with opposite charges and equal mass.
The lifespan of an electron-positron pair is very short, typically on the order of 10^-22 seconds. This is due to the fact that the two particles are constantly annihilating each other and turning into photons.
The main factor that affects the lifespan of an electron-positron pair is the energy of the particles. Higher energy particles can exist for longer periods of time before annihilating. Additionally, the presence of other particles can also affect the pair's lifespan.
No, an electron-positron pair cannot exist indefinitely. Eventually, the particles will annihilate each other and turn into photons. However, in certain conditions such as in a strong magnetic field, the pair can exist for slightly longer periods of time.
The existence of an electron-positron pair is important in particle physics because it helps to explain the conservation of energy and charge in particle interactions. The pair's short lifespan also allows scientists to study high-energy interactions and the behavior of particles at very small scales.