Energy Conservation - Understand Mass & Reactions

[r3za]

Hi,

I had a question about reactions. I actually know how the baryon number, the lepton number, and the electric charge conservation works for reactions, but what i do not understand is the energy conservation. I searched the whole web for it, but there was no page where I could understand the stuff.

i know that it has something to do with mass, that the mass of a neutron is higher than that of a proton.

For example: p + p > p + n ... i know that the electric charge is not correct, so I need a positron, but then the lepton number is not correct, so i need a ve.

>> p + p > p + n + e+ + ve ... but what about the energy, how can i find out if the energy conservation is oki, and what I have to add to make it work?

It would be really cool if someone could help me out here!

 

[dextercioby]

Conservation of 4momentum in a Feynman diagram (scattering or decay process) is fundamental.

Read pages 72 pp.76 from D.J.Griffiths' "Introduction to elementary particles",Harper & Row,1987.

Daniel.