I want to do data analysis and there are some processes called event generation and event reconstruction. I want to know these terms that what does it mean in particle collider? Please guide me.


closed as too broad by sammy gerbil, Emilio Pisanty, AccidentalFourierTransform, Kyle Kanos, rob Aug 10 '18 at 19:24

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  • $\begingroup$ Where did you find these terms? Have you tried searching the internet for explanations? Or this site? eg Differences between reconstruction- and generation-level variables in HEP data $\endgroup$ – sammy gerbil Aug 6 '18 at 23:11
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    $\begingroup$ I'm voting to close this question as off-topic because of insufficient research effort. $\endgroup$ – sammy gerbil Aug 6 '18 at 23:11
  • $\begingroup$ I have found these terms in BESIII Analysis. $\endgroup$ – user8288477 Aug 6 '18 at 23:13
  • $\begingroup$ Okay. To be more precise, could you please tell me the meaning of an event in the collider Analysis? Suppose I want to do the analysis of some charged mesons decaying into leptons. I have created 100 events for for this decay process and now I want to know each event carefully. How can I do this? $\endgroup$ – user8288477 Aug 6 '18 at 23:15
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    $\begingroup$ If you are new to particle physics, why don't you start with a simple introduction? eg opendata.cern.ch/record/50 from the CERN website. $\endgroup$ – sammy gerbil Aug 6 '18 at 23:29

In simple term, analysis of particle experiments needs two inputs.

Events from the detectors, i.e. the data have been processed so as to recognize particles and reconstruct a single event; the event is saved in a data bank and has a specific id.

That is event reconstruction. Here you see one reconstructed event .

Event generation implies a monte carlo program, where the quantum mechanical solutions given by the standard model of particle physics are used to throw (generate) an event to build up the probability distribution predicted for such events. This is an ideal event that has to be processed through the detectors again with monte carlo generators giving the probable detection tracks/signals, and gives simulated events at the same level as reconstructed events, so that the distributions can be compare. If the two agree the model is validated, if they disagree a different model has to be proposed ( a discovery made).

The level of reconstruction, i.e. if one stops at tracks and jets and showers, as in the image linked, or use the final four momenta assuming masses for the tracks and assigning jets to hadronic tracks, depends on the type of analysis carried out. One then compares the predicted by monte carlo generation distributions, to the distributions coming from the accumulation of reconstructed events.

Important to note that he word "reconstructed" can also be used for monte carlo generated simulation data, when they go through the process of reconstructing individual four momenta for the simulated event.

Reconstructed events can be a description of the generated events, depending on the context.


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