Higgs Hunters Talk

Useful quotes from the Talk boards

  • Turkwise by Turkwise

    There's a lot of good information, from scientists, moderators, and Zooniverse team members, scattered throughout these boards. I wanted to collect and categorize them to help people so they don't have to dig to find this information!

    First of all, the most important page on the site, the FAQ: http://talk.higgshunters.org/#/boards/BHH0000001/discussions/DHH00000np

    -----What to mark/not mark:------

    • ...while in many scientific contexts guessing may be bad, educated
      guessing is actually not destructive in citizen science! The reason
      is that many people see each image/object, and when we reduce the
      data from several people's guesses, we astonishingly very often find
      that, as a group, they have arrived at the right answer! It's one of
      the miracles of citizen science. This is the reason why, in our
      animal-photo projects like Snapshot Serengeti, we don't allow people
      to mark an animal as "unknown;" they have to give their best guess.
      More often than you (or they) would think, they produce the right
      answer as a group! And when they don't... when the scientists see
      that 20 people have guessed 20 different animals... they recognize
      that image as a difficult one, and flag it for expert analysis.
      Inaccuracy often tells the team as much about an image as accuracy,
      as long as everyone is trying their hardest. (DMZ, Zooniverse Team)

    • ...backwards means that the tracks continue "backwards" from the
      displaced vertex towards the center of the detector. This is an
      artifact of how the tracks are drawn, and does not indicate the truth
      path of the particles, if they really came from the vertex.
      (andy.haas, scientist)

    • Anything that is visibly offset from the center is interesting. Human
      eyes are better at making this call than we might think, so if you
      make your best guess you stand a good chance of being right.
      (alanbarr, Scientist)

    • There is no need to mark single white lines. As for lines that cross,
      you can mark them. If they cross at a wide angle they are probably
      not ocv's, so no need to mark those. (ElizabethB, Moderator)

    • Stray white lines can be caused by #cosmic #muon tracks, or by gas
      atoms being knocked about by the beam of the collider. It's good to
      mark them as 2-track vertices if you can manage. But because they can
      be other things they are less important to mark than multi-track
      vertices. (alanbarr, Scientist)

    • Circles or ovals are where the computer guesses a vertex is. It does
      a quite good job in slice, but terribly in normal and zoom. Feel free
      to ignore them. (koranzite, Scientist)

    • The colours [of the lines] are added by the computer, but sometimes
      the computer doesn't see all the tracks. Count all of them,
      regardless of the colour. (koranzite, Scientist)

    • Two lines crossing when one goes back to the centre probably isn't a
      vertex. For an example of a vertex where a line goes backwards near
      (but not exactly towards) the centre, take a look at the 'backward
      tracks' section of the field guide under classify. (koranzite,

    • Yes, muons are drawn in green. (Sometimes there are other tracks that
      are also green, sorry. But the muons go farther, into the outermost
      muon detector, and have thick red lines at the end of them.)
      (andy.haas, Scientist)

    • As far as angles are concerned, if the #ocv is really caused by a new
      type of particle moving away from the center, we'd expect to find at
      least some of the decay-particle-tracks to also be moving away from
      the center. (This is the physics of "Conservation of momentum" in
      action!) (alanbarr, Scientist)

    • Yes, you can ignore these [single/stray/random white lines]. All
      manner of particle interactions can cause them, but they are pretty
      dull and not caused by any exotic physics. (koranzite)

    -----Those Colored Circles:-----

    • Yeah, it is a remnant from a vertex found by the computer, but whose
      tracks have since all failed further quality criteria. So it is
      likely a "fake" or a known particle decay. (andy.haas, Scientist)

    • The circle is an artifact, no need to mark it. See the field guide :
      toughies (ElizabethB, Moderator)

    -----Red Dashed Line:-----

    • The red dashed line represents the direction of imbalance of momentum
      when all the detected particles are combined (peterwatkins,

    • It's probably one of the mysterious 'ghost' particles: neutrinos.
      (koranzite, Scientist)

    • No need to mark it as "unusual" though - we expect it when the
      collisions make neutrinos, which are (almost completely) invisible.
      (alanbarr, Scientist)

    -----The Muon Detector:-----

    • [rectangles in the outer blue circle] red = muon blue = jet from
      bottom quark yellow = photon green = electron (?) (andy.haas,

    -----"Something Weird:"-----

    • We don't have pictures of weird stuff - but we're hoping that people
      will see something weird and alert us! What could be weird? 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! andy.haas (Scientist)

    • Once you look at a few images you get a bit better feel for what's
      normal and what's not. (alanbarr, Scientist)

    -----Simlated Data:-----

    • Some of the data is simulated, some of it is real data. This is so we
      can check how good you all are at spotting vertices that have been
      artificially added. This is why you have been seeing so many
      potential vertices, as we want to train you to be really good at
      spotting them so when you stumble upon one in real data (which are
      quite rare) you will spot it easily. (koranzite, Scientist)

    -----Why you can't switch views:-----

    • You're presented with a random view for each classification.
      Switching between them is only supported during the talk. (andy.haas,

    • In fact we thought carefully about this, and there is a good
      scientific reason for serving up the images separately. It's because
      later, when we do a full statistical analysis of the classifications,
      they are much more suited for good statistical analysis if they are
      independent, and unbiased. So we get much more science per click this
      way. (alanbarr, Scientist)

    -----Slice View:-----

    • The name 'slice' is a little misleading, since this view is generated
      from a combination of the side and top views of the detector
      perpendicular to the beam direction. It's an artificial projection
      that allows us to reconstruct the location of a vertex in 3d when
      combined with the normal or zoomed in image, but it' is not what you
      would actually see if you cut a slice through ATLAS. So the short
      answer is no, there is only one unique slice image for each image.
      (koranzite, Scientist)

    • [The 'center' of Slice View] is indeed a horizontal line. (andy.haas,

    • The center on slice view is in the middle, vertically, of the image.
      There are ~10-20 small ellipses along that horizontal line where
      proton collisions have taken place. (In the other views, all the
      collisions are at the same spot, in the middle. But in the slice
      view, the collisions are spread out! This is because the colliding
      proton bunches are very thin (~microns) but fairly long (~cm's)).
      (andy.haas, Scientist)

    Please share anything you see that's useful, interesting, and helpful! I think it's a good idea to have this stuff in one place.


  • DZM by DZM admin

    Thank you so much!! Now I wonder if we could merge this with @jokergirl's FAQs thread to get this all in one place...

    @Turkwise, how would you feel about coordinating with @jokergirl , one of our moderators? She was going to work on cleaning up her own Higgs Hunters FAQs tonight.

    Maybe we could make a new (locked) topic that includes all of this, plus all of her stuff, and that could be the topic that we link to from the classifications interface? We're going to be adding a button to the interface that links to an FAQs topic here on Talk.

    It'd be good if it had all the answers to the questions we've seen many times over during the first week and a half consolidated in a single place, like you said.


  • Turkwise by Turkwise

    Well I'm not sure what you mean by coordinate, but as far as I am concerned you or anyone else can do whatever you want with this post.