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Monica Dunford | USLHC | USA

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SNO vs. TileCal

Last week I received the following comment from Chris and thought I might address it in more detail.

How does the work dynamic compare to your previous work on SNO? Is the TileCal working group your new “collaboration”? Do you feel lost in a sea of meetings? Does working with that many people mean there is enough organization such that it almost feels like *gasp* an industry job?

INCO_mine Ah, SNO! How I miss it! I had no idea what emptiness or the phrase ‘as far as the eye could see’ really meant until I had spent a winter in Sudbury, Ontario. When looking out over the landscape I was always simultaneously awed by the vastness of space and depressed by the physical scarring of the landscape from more than a century of mining. This picture perhaps shows a little of this. In the background is the head-shaft for shaft number 7. The Creighton mine, which is where SNO was located, has 11 shafts in total but only one, shaft number 9 is still used for passenger, equipment and ore transport. The only trees that can survive in the soil near the mines are these skinny white birch as seen in the picture’s foreground. But my advisor, Gene Beier used to tell me that 20 years ago there were zero trees. So life has been making a comeback in the area.

In the high energy physics world, the SNO collaboration was minuscule. Our author list of roughly 150 people could fit on a single page. That is compared to the ATLAS author list which last time I checked was 11 pages of names and 7 pages of institutions. But there are many similarities in terms of work dynamic between these two experiments.

Although ATLAS has an order of magnitude more people than SNO, TileCal is about the same size. In terms of experimental complexities, TileCal is also comparable with SNO. TileCal has roughly 12,000 electronics channels whereas SNO had 10,000 channels. But the major difference between SNO and TileCal, or SNO and ATLAS is that SNO was designed with one major goal in mind: measurement of the solar neutrino flux. And although SNO published other results such as a search for antineutrinos, the measurement of the solar neutrino flux was its main measurement. For the most part, everyone in the collaboration was focused on that goal.

In the TileCal community, people are largely interested in the calibration and studies of ‘jets’ (collimated showers of energetic particles which deposit energy in the Liquid Argon and Tile calorimeters). But there is a huge range of physics measurements to focus on such as measurements of the Top quark mass, discovery of the Higgs particle, or searches for new physics such as SUSY. Within a single physics group, there are members from every sub-detector, each bringing to the discussion expertise from his/her sub-system. In that sense I think it is easier to ‘get lost’ within ATLAS compared to SNO. Because the people working with you on TileCal might have totally different physics interests. There are so many different things to work on it is hard to decide what to work on.

Considering how many different institutions, sub-detectors, and physics groups there are, ATLAS is surprisingly unorganized (though not necessarily disorganized) and yet still functional. ATLAS can never be organized like an industrial company because there is no real power of ‘purse or sword’ within the administrative hierarchy. For example, most institutions are individually funded. So if institution A is unhappy with someone at institution B, institution A can appeal to the ATLAS administration but that administrative body has no power to remove anyone at institution B. Therefore to get what they want and need, the institutions, sub-detectors, physics groups have to negotiate with each other, trading the only resources they have: their people’s time, electronics/construction facilities, expertise, etc. And the elected ATLAS hierarchy has the very difficult task of trying to channel all of these independent networks in one general direction.

It is a thankless task, which is why I am glad that as a post-doc I am near the bottom of the chain where I have the luxury of being able to focus on the detector and the physics.

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No Responses to “SNO vs. TileCal”

  1. [...] US LHC Blog » SNO vs. TileCal Notes on life in a big collaboration, and the joys of Sudbury. (tags: physics experiment science blogs) [...]

  2. Monica
    Like you, I studied Chemistry; worked for four years as a chemist in industry; then got drafted & diverted into electronics by Navy training; got my BS in Chemistry; worked for three years as electronics engineer in plastics; continued in electronics for fourteen years at Tektronix, Inc, where I became Vice-President of Engineering, one aspect of which was visisting our customers at Brookhaven, SLAC, & Arnold Energineering Labs. I was fascinated; began to read extensively in particle physics, became addicted. and then have had incredible success in creating Infinite Particle Physics, an approach that requires just two fundamental particle and permits one to visualize particles and nuclides in three-dimensions, and calculate their mass-energies amd mass-deficits within 0.01%.

    What I hope to persuade you to do, is to bootleg a few tests to confirm these novel aspects of IPP:

    1. muons have ±1/2e charge
    2. muon-neutrinos have ±1/2e charge
    3. particles and photons are point-centered ellipsoidal oscillations in the packing-density of the bipolar particulates that comprise the polycrystalline space lattice. The in-and-out waveforms of photons are unaberrated, while particle waveforms are aberrated by the presence of a bound lattice defect or defect cluster at its center.

    These concepts, and many others are described in great detail on my web site, infiniteparticlephysics.com.

    Good hunting, Dick

  3. Chris says:

    Dick:
    Irregardless of my views on your theory, your post seems to be off-topic.

    Monica:
    Cool, thanks for the reply! That’s a neat insight on how ATLAS isn’t like a company: you’re stuck with your collaborators till the end. At least everybody I know that’s read this post has been freaked out by just the size of the author list! It makes you wonder what the dead-wood percentage for collaborators is (luckily my last name isn’t posted!). But, personally, it’s nice to hear that sub-detectors are sort of like a mini-SNO because it doesn’t sound like the day-to-day “who do I call for help?”-dynamic changes much.

    So the question I gotta ask is: isn’t your author list longer than the PRL page limit? :)

  4. Chris says:

    Also, why ATLAS instead of something like ALICE? Sure, ATLAS can possibly see the Higgs and SUSY, but it seems like experiments like ALICE are much harder experiments (disagree if you do!!). I’m strongly biased by seeing a bunch of RHIC talks I loved, but I’m curious why you decided to work on ATLAS instead of something else. I guess the detector is huge and doesn’t seem to have a budget, which provides for wonderful technical challenges, but why *this* detector?

  5. Monica Dunford says:

    My physics interests are geared towards the discovery of new physics, whether that be SUSY or something totally unthought of. ATLAS as well as CMS were designed with versatility in mind making them very ideal for these searches. Besides, discovery of new physics with proton-proton collisions is hard enough. Heavy-ion on heavy ion, that is really hard.

  6. Doug says:

    Dick:
    Regardless of Chris’ musings, I’m happy to find this post of yours. I’ve been unable to reach you by phone or email.
    I hope to contact you soon regarding IPP and the disappearance of your website. Contact me anytime at mrreadynet@gmail.com

    Chris:
    Irregardless? Seriously?

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