Reconstruction vs Identification

In summary, reconstruction and identification are two steps in a process to determine if an object is a jet. Reconstrution gives you "here, this could be a jet" and identification then says "okay, this jet candidate is probably from the right primary vertex and satisfies some other quality criteria".
  • #1
ChrisVer
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This is a fast-question/need of confirmation concerning the two: Reconstruction and Identification.
I am trying to "separate" what they mean.
For example when we reconstruct a jet, we apply several selection criteria that the object "jet" should satisfy. Is that correct? Then any object that satisfies those criteria is reconstructed as a jet and used as one afterwards. My confusion comes here because this implies an identification; the object is seen as a jet afterwards. Or I should better say reco-jet.
Identification on the other hand is also using other selection criteria + some variables fed in a BDT (or LLH) that are used to identify the jet as a fake (maybe from a tau) or not?

If the above is "correct" (if it's wrong then I have misunderstood something crucial), I don't see the reason for applying the two and not just going for ID alone. it's like going from city A (bulk events) to B("known" event type and kinematics) by passing first from another city C (reconstruction), rather than taking the straight way to B.
Thanks
 
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  • #2
ChrisVer said:
For example when we reconstruct a jet, we apply several selection criteria that the object "jet" should satisfy. Is that correct?
Right.

Reconstruction and identification are not always clearly separated. Experimentally, you often have a two-step process. Reconstrution gives you "here, this could be a jet" and identification then says "okay, this jet candidate is probably from the right primary vertex and satisfies some other quality criteria".
Generic jets don't have strong identification criteria, because nearly everything with energy deposit in the calorimeter is called a jet. The distinction is clearer for everything else.

Identification can use a BDT but does not have to.
 
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  • #3
mfb said:
Identification can use a BDT but does not have to.
hmm... I can't see that...
Wouldn't the ID come with a probability that the particle is what it's IDed with? I thought that BDT does that immediately by separating bkg to signal (and result to loose,medium or tight IDs). Is there an alternative way?
 
  • #4
ah... I think instead of feeding the variables in a BDT you could apply cuts on them...
 
  • #5
ChrisVer said:
ah... I think instead of feeding the variables in a BDT you could apply cuts on them...
Right.
And even with a BDT, the output is often used as "yes/no" - a cut on the BDT output.
 

What is the difference between reconstruction and identification?

Reconstruction and identification are two different processes used in science. Reconstruction involves piecing together information or data to create a representation or model of a system or event. Identification, on the other hand, is the process of determining or recognizing the characteristics or identity of a system or object.

When is reconstruction used in scientific research?

Reconstruction is often used in scientific research when there is incomplete or fragmented information about a system or event. It can also be used to create a simplified model to better understand a complex system or process.

What are some techniques used in reconstruction?

Some common techniques used in reconstruction include data analysis, computer simulations, and physical modeling. These techniques can help scientists visualize and understand complex systems or events.

How is identification different from classification?

Identification and classification are often used interchangeably, but they have distinct differences. Identification involves determining or recognizing the characteristics or identity of a system or object. Classification, on the other hand, involves categorizing objects or systems based on their characteristics or properties.

Can reconstruction and identification be used together?

Yes, reconstruction and identification can be used together in scientific research. Reconstruction can help provide data and information to aid in the identification process, while identification can help validate and improve the accuracy of the reconstruction process.

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