Higgs Hunters Talk

Higgs Hunters Hashtags

  • Whoandwhatitis by Whoandwhatitis moderator

    In response to this discussion posted by @Pickledbeats, I would like to invite the community to compile a list of hashtags with examples, discussions and other complementary information.


    The goal is to produce a resource which can be used to help volunteers quickly identify hashtags that may be used when they see certain events or patterns in an object.

    Please keep in mind that a comprehensive list of hashtags may not be feasible or exceedingly useful, because we are free to use arbitrary hashtags to describe an event.

    I think that it is appropriate to use this thread as a quick reference, but avoid using this as a comprehensive guide. It is very important to the scientists that we use our intuition to influence the way that we approach classification of objects in this project.

    Style Guide

    Suggestions for formatting posts:

    • List hashtags in alphabetical order.


    You can find a basic explanation of many of the terms used in this thread by checking the FAQ, or the ATLAS detector details page.


  • Whoandwhatitis by Whoandwhatitis moderator

    #bundle: Several particle tracks that appear to share a common origin, but do not meet at a vertex.

    #diametric: Many particles (or lots of energy) located on opposite sides of the detector, with relatively little between.

    #messy: Objects which are complicated by many crossing lines, which can make it difficult to find off-center vertices.

    #oval: Frequently used to indicate that a computer-drawn colored oval or circle appears in the images. The circles and ovals can be ignored.

    #sim: Used to tag a simulated (or suspected simulated) object. The Higgs Hunters interface displays this information at the bottom-right corner of the image in the objects' Discussion page.

    From scientist @andy.haas:

    Lots of tracks in one tight bunch, or coming out at weird angles but
    not forming a vertex, or a big amount of tracks on one side but the
    other side, or lots of energy in the calorimeter (the red/green areas
    beyond the tracker), or things in the muon system (the outermost
    detector)... what ever looks weird to you!

    From the Examples

    These hashtags are mentioned beneath the image in the classification interface.

    #backwardtracks: Computer-generated artifacts which may not reflect the true path of a particle. These are drawn so that they originate nearer to the beam line than the particle which they represent.

    #ocv: An off-center vertex.

    #lots: Many particle tracks which originate at a common off-center vertex.

    #toughie: Indicates that the object may be difficult to classify. Remember, any of the three available views may be displayed in the Classification interface, and these can present varying levels of difficulty.

    As @Pickledbeats mentioned, he would like to know more about #yellowfencepanels and #missingmuon.

    #yellowfencepanels: At this time, I see 105 results in a search for this hashtag, all of which are from comments in 2014. My guess is that this is a reference to deposits of energy (shown in yellow) in the most narrow section of the electromagnetic calorimeter in Normal view.

    #missingmuon: A red rectangle in the muon spectrometer area indicates a muon detection, but the green line leading to the red rectangle is missing. Use this when there is only zero or one green lines visible. If there are additional red rectangle without matching green lines, then it's up to you to whether you use the #missingmuon hashtag.