Creation of Matter

1. Jun 4, 2015

ArmanCham

Lets suppose we have a photon and it will gonna create a particle particle mass is $16.10^-29$ kg.I used $E=mc^2$ to find the solution and I found 90 MeV but the answer is 180 where did I made wrong.

Thanks

Last edited: Jun 4, 2015
2. Jun 4, 2015

Sagar Singh

particle mass not clear

3. Jun 4, 2015

Staff Emeritus
If you don't show us the calculation, it will be very difficult to tell you where you went wrong.

4. Jun 4, 2015

ArmanCham

16.10^-29 kgxc^2 is equal 16x9x10^-13 joule=144x10^-13 joule I convert this MeV and I found 90 MeV but the answer is 180MeV

5. Jun 4, 2015

ChrisVer

I guess because you need 2 particles at the end?

6. Jun 4, 2015

Sagar Singh

you forget momentum conservation

7. Jun 4, 2015

ArmanCham

I thought we need two photons to create a particle but I am not sure

8. Jun 4, 2015

Me ?

9. Jun 4, 2015

Sagar Singh

yaa momentum conservation is must,

10. Jun 4, 2015

ArmanCham

So final Answer is we need two photon ??

11. Jun 4, 2015

Sagar Singh

ye
yes

12. Jun 4, 2015

ChrisVer

I wasn't thinking about 2 photons...rather about 2 particles at the end...
$\gamma \rightarrow 1+2$

13. Jun 4, 2015

ArmanCham

But theres one particle

14. Jun 4, 2015

ChrisVer

you can't get 1 massive particle from 1 photon....
Simply because that would violate energy/momentum conservation. For the massive particle you can go to a frame where its momentum vanishes (rest frame)...at that frame, the photon's momentum can't be zero (because momentum=energy for photons, so you would get nothing), and you get a violation of energy/momentum...

15. Jun 4, 2015

Staff Emeritus
We are 15 messages into this, and we don't even have a clear idea on what the question is - people are still trying to guess.

16. Jun 4, 2015

ArmanCham

The question is we have one photon and it creates a particle we know particle mass but intersting thing is answer says photon energy is twice a particle energy why theres extra energy ?

17. Jun 4, 2015

ArmanCham

Thats make sense I thought feymann diagram we need one boson and two fermion to make a correct "feymann diagram" there cant be two boson and one fermion.So you are saying 180Mev will create two 90Mev particle or 180 Mev will create 90 Mev particle 90 Mev photon

18. Jun 4, 2015

ArmanCham

I found the answer I am so so sorry.

19. Jun 4, 2015