RE: NuSAG Talk version 3

From: Steven Biller (
Date: Sat May 28 2005 - 19:09:39 CDT

  Hi Mike,
  Thanks for the new draft!
  Here are a few (hopefully helpful) comments:

  Side 1
  Our "design goals" have certainly never centered around the value
of sin2(2theta) of 0.013 and I don't ever remember discussing the
required reach of a 90% CL (which, again, isn't stated here regarding
what you call "sensitivity" but should be). I think what is probably
the closest to what we ideally wanted at was a sensitivity at the level
of 3 standard deviations for a sin2(2theta) of 0.01.

  At this point I feel I must again express my unease at separating
"discovery potential" from "sensitivity" and, indeed, even in that
choice of wording. Personally, I don't think a 90% CL means much
at all in this business and I don't think we should even risk giving
the impression that we'd settle for a 90% CL on anything by
highlighting it as some important goal. An upper bound on theta13 will
be just as important (argueably more so, if it turns out to be small)
as a measurement and we should apply the same rigid criteria to both.
Also, this experiment is not merely about a "discovery potential"
its about us being able to make a definitive and precise measurement
of a fundamental parameter. If, for example, it turns out that
Double-Chooz sees a 2.5 sigma or more effect before us, they may well
claim "discovery," but OUR experiment will then nail this beyond
all doubt and OUR precise determination will be the one used by
everyone in the community for years and years to come. I know other
proposed experiments may play with 90% CL intervals to sell their
project, but I think they just looks silly and think we would ultimately
look much better to our very learned reviewers if we made it clear up
front that our standards are higher and we're not looking for anything
short of 3 sigma, even for limit.

  Slide 10
  You need to spell out what you mean by "maximises data samples"

  Slide 11
  Same issues as with slide 1
  Slide 20
  This slide still does not work. Whatever words are said, the eye
  is drawn to a figure which, on the face of it, shows a much more
  dramatic effect for the 2-zone design and this is what sticks
  in the mind. At the very least, a shaded region needs to be shown
  where the energy shift is constrained to +-0.3%. Though, even this,
  may draw some skeptcism about whether it can really be pinned
  down to that level. On looking at this more, I definately think
  a 'before' and 'after' plot would be MUCH better. In a short
  presentation like this, I think it's important to leave the right
  visual impressions that will stick around after the words have
  Slide 25
  You need to make it clear that your drawing is really just a
  cartoon and does not necessarily represent how the shield will
  actually look. Even aside from the fact that we're pursuing
  alternative designs, you may get asked about things like
  access to the neck, which is in your bullet points but not
  in your sketches.
  Slide 28
  I think it's worth noting that you really do need both reasonable
  depth and well-matched and well-understood overburdens at near and
  far sites in order to do 12B to half a percent. That is, we should
  strongly imply that only we can do this.... the others may well
  claim that, of course, they can look at things like this as well,
  but they won't be able to genuinely make use of it as a convincing
  calibration of the relative fiducial volumes to the necessary level.

  Slide 31 and, to a lesser extent, 32
  You knew I was going to complain about this give my previous
  tirade about 90% CL !

  Slide 35
  I don't believe it has been demonstrated, even in a "first analysis"
  that ES systematics can be controlled to 1%. Questions have been
  raised which may well be "show-stoppers" and these have not been fully
  addressed, which is one of the points of having an ES review.
  This phrase needs to either be dropped or substantially softened.
  I would advocate the former.
  Along a somewhat similar line, I would alter the highlighted box
  to read, "Braidwood is unique among theta13 experiments in
  HAVING THE POTENTIAL OF addressing this physics..."
  Slide 38
  Same gripe about "Sensitivity" vs "Discovery potential"

                                            - Steve

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