# Homework Help: Pair Production in Vacuum

1. Dec 17, 2009

### Phyisab****

1. The problem statement, all variables and given/known data

What is the uncertainty in the life time of an electron and positron produced in a vacuum?

2. Relevant equations

$$\Delta E\Delta t=\frac{\hbar}{2}$$

3. The attempt at a solution

$$\Delta E\approx1.6\times10^{-13}J$$

$$\Delta t\geq\frac{\hbar}{2\Delta E}\approx 3ps$$

(edited for Tex)
This is the solution my professor had to this problem in his notes, but I am quite sure that the final answer of 3ps is a typo. I believe that Delta t is more like 3 x 10^-22 s. Can anyone clear this up for me?

Last edited: Dec 17, 2009
2. Dec 17, 2009