00:01
Now we have a sigma barion that is decaying into a lambda barion and a gamma ray.
00:10
We want to find what is the gamma ray energy, which is basically e -gama.
00:19
Now the thing to take note over here is that our original sigma particle is at rest when it decays, so it means that the total momentum of this system is zero.
00:31
Which will imply that momentum of the lambda baron is the same in terms of magnitude and opposite in direction to the momentum of our gamma rate.
00:44
This is by conservation of momentum.
00:49
By conservation of energy, the initial total energy is just the rest energy of the sigma variant.
00:59
The final energy is the energy of our energy of our variant.
01:03
Our lambda baron plus the energy of our gamma ray.
01:14
Now, what we need is to understand that our gamma ray energy is equals to p gamma times c, right? because it's massless, so by the energy mass relationship, the total energy of the gamma ray is just p times c.
01:38
And so this means that, we can actually bring in e gamma into the total energy for lambda barion, in which its total energy is equal to its momentum times c square plus its rest energy square and since momentum of the lambda baron is the same as the momentum of our gamma ray can we place this with the momentum of the lambda baron.
02:18
So this is actually equals to just e gamma square...