# Could anyone help me to recognize the Atlas results?

1. Jul 10, 2013

### kalok87

Hallo, Dear particle physist,

Despite I am major in biophysics, the particle physics looks attractive to me... So I just used Atlantis to check some experiments result from internet... Although I can find some resultant particles. I still cannot understand how to draw a Feynman diagram for them, because I have not learned the mechanism about it.

If it is possible, could you please give me some hints to do it? (In the attachment you can find those visualized data.)

For example, in the first picture (No.2 in the Data): I found there are electrons and muons and hadrons (do not know whether neutron or proton, they are in the same path as muons.), what is the Feynman diagram to describe this process?

Thx.

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2. Jul 10, 2013

### Staff: Mentor

3. Jul 10, 2013

### kalok87

Hi, Jedishrfu

If I want to start to draw a diagram in this case (for Atlas, LHC), what should I draw at left hand side? Should I draw $P + P \rightarrow$ ( because it is the collision of 2 protons) or
$W \rightarrow$ and $Z \rightarrow$ ?

4. Jul 10, 2013

### Staff: Mentor

It is not possible to write the whole interaction with a Feynman graph.
Protons are not elementary particles (they consist of quarks and gluons). In a typical "interesting" collision, one particle ("parton") with significant energy from one proton collides with a parton from the other proton, releasing a lot of energy. The interesting particles (like W and Z bosons, top-quarks, Higgs and whatever) are produced in that interaction, and that can be written with a Feynman graph (example).
Apart from that hard interaction, you always have the rests of the protons hanging around - they can lead to many new gluons and quarks and those produce additional particles quickly afterwards.

Event displays like your images are not a practical method to study particle decays.