Quick Links

A few quick items:

  • I was very sorry to hear recently of the death of David Goss (obituary here), a mathematician specialist in function fields who was at Ohio State. David had a side interest in physics and was a frequent e-mail correspondent. From what I recall I first heard from him in 2004 soon after the blog started, with my first reaction when I saw the subject and From line that of wondering why David Gross wanted to discuss that particular article about physics with me.

    Over the years he often sent me links to things I hadn’t heard about, with always sensible comments about them and other topics. I had the pleasure of meeting him a couple years ago, when he came to Columbia to drop off his son, who is now a student here. My condolences to his family and friends.

  • The AMS has a wonderful relatively new repository of mostly expository documents called Open Math Notes. The quality of these seems to uniformly be high, and this is a great new service to the community. I hope it will grow and thrive with more contributions.
  • Peter Scholze has now finished his series of talks at the IHES about his ongoing work on local Langlands, the talks are available here.
  • Jean-Francois Dars and Ann Papillault have a web-site called Histoire Courtes, with short pieces in French, many of which are about math and physics research.
  • The LHC is starting to come to life again after a long technical stop. Machine checkout next week, recommissioning with beam during May, physics starts again in June.
  • There’s a new book out with string theory predictions from Gordon Kane, called String Theory and the Real World. Kane has been writing popular pieces about string theory predictions for at least 20 years, with a 1997 piece in Physics Today telling us that string theory was “supertestable”, with a gluino at 200-300 GeV. Over the years, his gluino mass predictions have moved up many times, as the older predictions get falsified. I don’t have a copy of the new book, but at Google Books you can read some of it. From the pages available there I see that

    the compactified M-theory example we will examine below predicts that gluinos will have masses of about 1.5 TeV…
    The bottom line is that with about 40 inverse fb of data the limits on gluinos are just at the lower range of expected masses at the end of 2016.

    Right around the time the book was published, results released at Moriond (see here) claimed exclusion of gluinos up to about 2 TeV. Assumptions may be somewhat different than Kane’s, but I suspect his 1.5 TeV gluino is now excluded.

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19 Responses to Quick Links

  1. new says:

    since LHC latest results push gluino masses above 2tev above Gordan Kane’s limit of 1.5 tev, Is there an upper limit Gordan Kane can push gluino masses ?

  2. Rob says:

    New
    The Planck scale.

  3. my Milkshake brings all the Boys to the Yard says:

    Kane must be aware of this kind of criticism. What does he say in response?

  4. Jeff M says:

    @Rob

    OK, that would be funny if it weren’t true.

    Peter, thanks for the AMS link, looks great.

  5. SteveB says:

    Does someone have information on why the LHC technical shutdown was so long? 4 (or was it 5) months? Also, I occasionally used to look at the Morning Briefings on the Indico site. I could get there until last week (there was no new information for 2017), but now it brings up a CERN authentication screen — keeping me, the public, out. Anyone know why they changed their policy — or is there a new site? Here is the old one (that I found on this blog some years ago):
    https://indico.cern.ch/category/6386/
    Thankfully, the Vistars site still works:
    https://op-webtools.web.cern.ch/vistar/vistars.php?usr=LHC3

  6. Peter Woit says:

    Re Kane,

    I should have made clear that his viewpoint is a minority one among string theorists, most of whom at this point acknowledge that in its current state you can’t get testable predictions out of string theory. Kane deals with this basically by saying these string theorists are ignorant, see for example page 6 of his Munich presentation, available here

    http://sites.lsa.umich.edu/gordonkane/wp-content/uploads/sites/117/2014/07/munich-final.pdf

    As far as I know he’s never addressed the question of why, given so many previous failed predictions, anyone should take seriously his latest ones (few people do).

    Steve B,

    This was scheduled a long time ago to be a longer shutdown, an “Extended” year end technical stop. My understanding is that the main reason for this is the time needed for installation by CMS of an upgraded pixel detector, but presumably there are many other sorts of maintenance that could take advantage of the longer time period.

    Once recommissioning and daily meetings start, perhaps information from these will again be available publicly. If not, LHC fans could politely ask, explaining that they appreciate getting direct news of the health of the star.

  7. MathPhys says:

    ” Kane deals with this basically by saying these string theorists are ignorant, see for example page 6 of his Munich presentation”.

    I recommend page 7 and page 8.

  8. John McAllison says:

    SteveB,

    As Peter has pointed out, the extended year end technical stop (EYETS) was planned before 2017. This document is from Jan 2015:
    https://indico.cern.ch/event/387137/contributions/1818419/subcontributions/157604/attachments/773229/1060436/YETS1516.pdf

    This link gives a brief outline of what’s been going on during the technical stop:
    https://home.cern/cern-people/updates/2017/03/eyets-report-2017-busy-year-ahead-accelerators

  9. Shantanu says:

    Peter and others:
    There is supposed to be new B-physics results announced today

    https://indico.cern.ch/event/580620/

  10. david_n says:

    Thanks for the AMS information; looks very helpful.

  11. modda says:

    Yes, you were right to be surprised when you thought David Gross wanted to discuss with you.

  12. Peter Woit says:

    Shantanu,

    Tommaso convincingly makes the case for skepticism here

    http://www.science20.com/tommaso_dorigo/lhcb_measures_unity_finds_06-225038

  13. Doug McDonald says:

    As to the morning meetings error note, this has happened before. In at least one
    case, it was at a time like this and they were doing some changes to the way the
    computer systems were do it. I would not worry for at least a few days.

  14. Tim says:

    Clearly, the masses of supersymmetric particles are not constant, but increase with time, as predicted by string theory and the multiverse.

  15. physicsguy says:

    Peter,

    note that Tommaso is not an expert on flavour physics, and in fact a comment by an expert below his post very convincingly argues why what Tommaso writes does not make much sense.
    Still I would not bet with Tommaso because I think the odds that it is new physics are nevertheless below 50% in my opinion, maybe 20% or so.

  16. neil says:

    The lepton universality tests by LHCb are quite interesting. After the 750 GeV circus, no one wants to hype a 2.5 sigma signal, but there appears to be tantalizing hints from a number of sources. I am looking forward to results from new data later this year on potential BSM physics.

  17. Sidi M. says:

    Hi everyone,
    Thank you Peter for the Histoires courtes link, amazing audio stuff, we’ll sleep less stupid.

  18. Milkshake says:

    They’ve had 3.3 sigma signals that turned out to be nothing before.

    I think Kane is wasting everyone’s time. (He’s always talking about his latest predictions at conferences.) Someone should have a polite discussion with him.

  19. Jim says:

    Hi Milkshake,

    I didn’t follow LHCb so closely. Can you remind me which 3.3 sigma signal turned out to be nothing?

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