I Missing energy for new physics

[Silviu]

Hello! I understand that missing energy is a sign for new physics (BSM, supersymmetry). However, almost all the time, the missing energy is associated with neutrinos. How can someone decide if some missing energy comes from somewhere else, other than neutrinos? Thank you!

 

[mfb]

Estimate how many events you expect from neutrinos, then see if you find more than that. Binning the analysis in missing transverse momentum or similar observables helps to distinguish between neutrinos and BSM particles, as they will generally lead to different distributions.

 

[ChrisVer]

Hello!

Hi

I understand that missing energy is a sign for new physics (BSM, supersymmetry). However, almost all the time, the missing energy is associated with neutrinos

Well, not exactly... there is missing energy due to:
1) Standard Model processes (real missing ET)
2) Mismeasurement of the energy of the particles in each event (or even losing some objects).
The large missing energy is more likely to come from neutrinos, rather than a mismeasurement of your hard particles.

How can someone decide if some missing energy comes from somewhere else, other than neutrinos?

Well this is kinda vague... one example that comes to my mind out of the blue:
Are there standard model processes that don't produce missing energy due to neutrinos? If yes (and it's a yes, for example Zmumu or Zee), then you can try and pick up those processes, and test how much missing et you actually measure... since there is no "neutrinos" in these processes, then you know that the missing et is actually coming from your mismeasurement...