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RE: Scrutinizing a dark top model with colliders, cosmology and astrophysics
Okay, this might be a dumb question but I have to make it: could we essentially touch dark matter even though it is not electromagnetically interacting?
The key point consists in using the conservation of the energy (and the momentum) to reconstruct what is invisible.
So I get that they basically gather data regarding energy and momentum variations in the system and then create a virtual model? Correct me If I'm wrong. (I know you would :P).
That was a wonderful, glamorous blog!
See what I did there??
Thank you for your efforts, @lemouth!
Keep up the great work!
Dark matter can be sensitive to weak interactions, or even to new forces. It can also interact with the Higgs boson. Those are varied option to make it interacting (always super weakly) with the particle of the Standard Model.
It is actually different. One is colliding two particles along a so-called collision axis (that we may call the z-axis to fix the ideas). In the initial state, there is thus exactly zero momentum in the transverse plane (the Oxy plane) since our colliding particles do not move within this plane.
Now let us move on with the final state. ,Our detectors investigate what is going on transversally to the collision axis (i.e. in the Oxy plane) because the proton remnants pollute what is going on along the z-axis. From the detector records, one can reconstruct the final state and measure the total amount of transverse momentum in it (the amount of momentum along the Ox and oY directions).
By momentum conservation, we know in advance that this transverse momentum must vanish. If however often does not. Therefore, we calculate what is missing to make it vanishing. This is the missing momentum which we associate with dark matter in our case. The missing transverse energy is the norm of this vector.
Is it clearer?
Well, it's a lot clearer now, thank you for taking the time to leave such a detailed response. I just wish I could reward your response accordingly.
I get that proton remnants have no effect in the Oxy plane, thus the amount of momentum in this plane that vanishes due to momentum conservation is considered to be somehow related to the presence of dark matter.
I think I got it, right?
Again, thanks for this mini 'private' lecture, lol!
This is a very good summary. Just to emphasize: we measure the total momentum in the transverse plane (Oxy) and what is missing so that the sum of all contributions from all particles is called the "missing transverse momentum". This could of course come from neutrinos, but if the amount is large, this may be connected to dark matter. At the end, it is a matter of confronting predictions of the Standard Model to data and see whether we have room for dark matter or not. So far: nothing non standard :(.