By high energy I mean 100+ MeV gamma rays. I think that at this energy of photons, pair production is the dominating absorption process. So, as known, in pair production an electron and a positron ...
Say a 1 MeV gamma ray is shielded by 1 cm (halving thickness) of lead. Now, what does "havling the intensity" mean ? Like will the new gamma ray exit with energy of 0.5 MeV ? and by that we can say ...
I know the products of the annihilation, but I don't know how much energy each particle has or gets. For example I know that 1876 MeV is released for each annihilation. Now, this energy is distributed ...
I cannot find the answer to the above question. I know that para-positronium is created with a probability of $25\%$ and decays into 2 photons, while ortho-positronium is created with a probability ...
Are scalars starting at around 1300 MeV analogous to some kind of sound in the vacuum glue? Background: There are scalars starting at around 1300 MeV which are probably some combination of ...
This should be easy, but I think I have a mind-block... For $\beta^-$-decay, what is the maximum possible momentum for the electron? The two equations I can use are conservation of energy and ...
We don't normally consider the possibility that massless particles could undergo radioactive decay. There are elementary arguments that make it sound implausible. (A bunch of the following is ...
The Pierre Auger Observatory site mentions the detection of a 3E20 eV (48 J) cosmic ray whose energy, well above the GZK cutoff, was based on an analysis of its atmospheric shower. This was equivalent ...