Missing energy using atlas dataset

Hey there, I’m new to root framework,

  1. I’m trying to calculate missing transverse energy mET, using transverse momentum of particles in the final state.
    but I’ m not sure how to analyse after calculating mEt values
  2. also I’ve found variables such as met_et and met_phi in the atlas 13 Tev dataset,
    so is missing energy values already there in the dataset or do we g=have to calculate them ourselves using the pT formula below.

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Hey, it’s not really a ROOT question, but I happened to know the answer:
met_et is the magnitude and met_phi is the direction of the missing energy vector.

If you would be calculating it yourself, you would get only a rough approximation of that, because ATLAS leaves out a lot of particles (and energy depositions) from the public files. You would need them to do the calculation.

@StephanH
Thankyou for your response,
so if met_et is the magnitude of missing energy it means that we do not have to calculate it ourseleves it is already given in the dataset, whatever analysis we want to do with missing energy values we can do it with met_et and met_phi?

as first I was trying to calculate it myself, then came across these variables met_et and met_phi
so I got confused that if we already have value of missing energy in the dataset it means we dont have to calculate it ?

Exactly. :slight_smile:

Thankyou so much, saved me big time :slight_smile: