Event Display Scanning For Beginners

This is the wiki page for the NOvA Event Display Scanning. The intention is to provide answers to the questions that you might have as a newbie in the scanning effort. The goal is to catch event displays that have the potential to become a neutrino candidates after further analysis.

Starting (getting things ready)

  • Instructions for Running the Scanning Display GUI:
  1. Assuming you are in one of the NOvA virtual machines (i.e. nova02), set up your environment using development release (i.e. setup_nova).
  2. Run the scanner by typing numi_scan and wait for the GUI to load. That should take a couple of seconds BUT less that a minute.
  3. After that, on the terminal you'll read the following:
    Hello <username> I've found a file for you!
    * Please wait a moment while the event display starts.
      (You won't see the normal start up scrawl...)
    * When it starts, open Window->Scan Window.
    * Please place the scan window over event number in upper right corner.
    * Please scan all the way to the end of the file.
    * Please DO NOT use the Back button.
Please be aware of the following once the Event Display GUI has appeared:
  • In the upper left menu click on Window -> Scan Window and place it over the event number in the upper right corner (why?).
  • When looking to an event, you can make decisions on it based in a combination of intuition, physics knowledge and perception. According to that, fill the charts in the Scan Window and/or write comments. You can also take a look at [Scanning Rules] for references.
  • Once your decision on the current GUI event is made, DO NOT navigate using Previous/Next or forwards/back buttons, instead press Record in the Scan Window if you want to go to the next event.
  • If you did a mistake and want to go back one event? (EXPECTED).
  • You can always zoom in to a different XZ and YZ range by clicking and dragging on the number labels of the GUI. You can unzoom by giving left-click -> UnZoom or click on Reload button in the upper left (remember that to do so your pointer has to change into a 'hand').
  • The aspect ratio of the events is not protected, so try to unzoom one last time before you click on Record to see the whole picture.
  • Other options are available in the Edit menu on the upper left.
  • To exit the GUI go to the upper left menu and click File->Quit.

NOTE: If for some reason when scanning your results become invalid (due to a network interruption, power outage, crash of the event display GUI, etc) try to send an e-mail to Gavin Davies () or Michale Baird () with your username and the time of your scan so that your results can be removed without any other complication.

Further reference to the Event Display GUI: Running the EventDisplay

EXAMPLE: 2013-12-06 Tutorial at FNAL

For the purpose of this tutorial and as an illustration, a sample file created by Michael Baird was used. It contains events that are not a sample for the actual neutrino scanning search so they should not be considered seriously.

Recalling the previous instructions: On a NOvA machine and setting development without actually doing 'srt_setup -a' you can open the sample file:

nova -c evd_numi_2db.fcl /nova/ana/users/mbaird42/numi_scan_example.root

After just a couple of seconds BUT less than one minute, you'll have the evd GUI active:

FarDet EventDisplay Scanning GUI with Scan Window

From this image we can appreciate that:

  • The timing window in the bottom left has been removed.
  • Blue solid line is a slice or cluster (bag) of hits, associated/correlated between themselves. The intention is that each slice corresponds to one neutrino interaction.
  • Blue dotted lines represent tracks (collection of hits) with a reconstructed path through them, i.e. CosmicTrack in this case.

After is decided what is the possible nature of this event and once you have filled the Scan Window charts and/or writing some comments, the next step is click on Record for continue scanning the next event.

Scanning Rules (what to look and how)

  • MC and Data: avoid becoming bias!

FarDet Event classification (tentatively).

  • Typical event
  • Logic Flow chart
  • Technical Details
  • Event Categories:
    • Golden-the ones that are candidates for going to the press.
    • Interesting-the ones that have something that make them not the right one.
    • Not Candidate-the ones that are not.
    • Others that not:Low plane count-the ones that have trouble fulfilling cuts.
  • Failure mode examples

Reporting (Did you find 'something'? What's next?)

  • Procedures:

Other links and references

Recent pdf's in docdb:


Any other useful stuff.