Never mind the Higgs, where’s the Supersymmetry?

There’s been a big conference on High Energy Physics going on in Grenoble since last Thursday, which I’ve been following a little bit via Tweets from various participants and links to blog articles contained therein. The media seem to be almost exclusively focussed on the Higgs boson but, as is made clear in a Guardian blog article by John Butterworth, the situation is that the latest data from the Large Hadron Collider do not provide clear evidence for it yet. Strangely, though, the Guardian ran another piece at the weekend claiming that “CERN scientists suspect a glimpse of the Higgs”, which appears to have been based on a blog article which offers various possible interpretations of a set of measurements which lie at the margin of statistical significance. It must be very frustrating not having a clear detection, but this  strikes me as clutching at straws. Far better to wait for more data before speculating in public. Nobody really expected to see the Higgs so soon, so it’s surely better to wait for more data rather than  over-interpreting what’s there. Let’s put it down to overenthusiasm.

However the real point of the latest news is not in my view the lack of, or marginal nature of, evidence for the Higgs Boson. It’s the extremely strong limits that have been placed on supersymmetry. This is of particular (geddit?) interest to me as a cosmologist because supersymmetric theories provide us with plausible candidates for the non-baryonic dark matter we think pervades the Universe.  The possibilities include fermionic counterparts of the bosons that mediate the standard model interactions. The photon, for example, which is a boson, mediates the electromagnetic interaction between charged particles; in SUSY theories it would have a fermionic partner called a photino. There would also be the Higgsino (assuming there is a Higgs!), gluino, gravitino and so on. Supersymmetry is a beautiful idea and many theorists love it to bits, but there isn’t a shred of evidence that has anything to do with the way nature is.

The search for supersymmetry is thus more directly relevant to my work than the Higgs, in fact, but the Large Hadron Collider was largely “sold” to politicians and the public in terms of the quest for the Higgs.  That’s the MacGuffin, as Alfred Hitchcock would have said. Actually the LHC will do many other things, but I guess it’s easier to make the case for funding to government if you have one Big Idea rather than lots of smaller ones.

Anyway, a piece from New Scientist today hits the nail on the head. While the Higgs search may or may not be producing tantalising clues, the searches for supersymmetry has drawn a complete blank. Zilch. Nada. Not the merest smidgeon of a scintilla. The class of supersymmetric theories is broad and no doubt many possibilities remain viable; the current measurements only rule out the “minimal” variety. But I think this is a timely reminder not to take nature for granted. Perhaps an  ugly fact is about to slay a beautiful hypothesis…

UPDATE: Bookmaker Paddy Power has shortened the odds on a Higgs discovery this year from 12-1 against to 3-1 on.

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15 Responses to “Never mind the Higgs, where’s the Supersymmetry?”

  1. Tom Shanks Says:

    There wasn’t much discussion about the lack of detection of the neutralino by LHC at last week’s Galaxy Formation conference in Durham. Indeed, the less lab evidence there is for the particle ( it now has to have mass beyond a TeV, at least in the simplest models) the more enthusiasm for CDM there seemed to be. The notorious problems set by dark energy and the various suggestions that the CMB evidence may still be subject to the odd systematic (eg arXiv:1107.2654) make this enthusiasm all the more puzzling. To be fair, one Prof CS Frenk did report that the (missing) satellites problem for CDM may have taken a turn for the worse – the luminosity – mass relation may be wrong, if only at the 2 sigma level. But otherwise the confidence in the CDM galaxy formation paradigm appeared undiminished. As Rob Kennicutt remarked in his opening talk – the number of people who don’t believe the standard model are now fewer than those that believe that Barack Obama was born outside the US……

  2. This is a bit random…but I find the colour scheme on your site very painful to read (so much I cannot do so for more than a few minutes). Apparently this is not uncommon with this colour scheme – and the solution I just found? Press ctr+apple+cmd+8 on my mac to invert the colour scheme – then I can read your site without problems (and hopefully this tip helps others too!)

  3. “As Rob Kennicutt remarked in his opening talk – the number of people who don’t believe the standard model are now fewer than those that believe that Barack Obama was born outside the US……”.

    Is there a significant correlation between the two groups of heretics?

    Does Donald Trump believe in the standard model? (Consider the fact that he is married to a standard model.)

  4. Tom Shanks Says:

    “Is there a significant correlation between the two groups of heretics?”

    Only among those who believe his name was changed from Baryonic Obama…

    “Does Donald Trump believe in the standard model? (Consider the fact that he is married to a standard model.)”

    Ivana idea he still prefers the previous model…

    (Am not sure this was worth the effort involved!)

  5. Tom Shanks Says:

    I just remembered the experimental work by J.J. Hudson et al 2011, Nature 473, 493 at Imperial College measuring the “roundness of the electron”.

    To quote: “In particular, the popular idea that new supersymmetric particles may exist at masses of a few hundred GeV/c2 (where c is the speed of light) is difficult to reconcile with the absence of an electron EDM at the present limit of sensitivity.”

    EDM is the electric dipole moment.

    Am wondering if the new results from LHC make this problem for SUSY any worse. Anyone know?

    • telescoper Says:

      The current experimental data seem to exclude masses less than the TeV level. I think at these scales SUSY particles would be consistent with the result you mention, but I’m not an expert.

      • Tom Shanks Says:

        From my uneducated reading of some of the refs quoted by Hudson et al I think you are right – Msusy>1TeV may be OK for the electron EDM.

  6. [...] (probably ill-informed) earlier post about particle physics seems to have generated quite a lot of traffic, so I thought I’d reblog this short article [...]

  7. [...] The Large Hadron Collider (LHC), switched on to the accompaniment of great fanfares a few years ago, provides a nice example of how the MacGuffin actually works pretty much backwards in the world of Big Science. To the public, the LHC was built to detect the Higgs Boson, a hypothetical beastie introduced to account for the masses of other particles. If it exists the high-energy collisions engineered by LHC should reveal its presence. The Higgs Boson is thus the LHC’s own MacGuffin. Or at least it would be if it were really the reason why LHC has been built. In fact there are dozens of experiments at CERN and many of them have very different motivations from the quest for the Higgs, such as evidence for supersymmetry. [...]

  8. [...] we don’t know for sure, and as a matter of fact I think CDM is still favourite. But if the LHC rules out supersymmetric CDM candidates and the astronomical measurements continue to defy the theoretical predictions then the case for [...]

  9. Check out http://supersymmetryart.com The staight line drawings by Frank MIngrone that create these beautiful and intricate patterns that, as the lines are infinitly extended, the pattern continues to replicate. Frank used to joke, “it’s not much, just the mathematical secret of the universe.” I’m seeking an orginazation to help introduce Frank’s drawings and the mathematics behind there creation.
    Thank you. Jim Souther

  10. Frank Mingrone was a self taught mathematician. I set up a web site, http://www.supersymmetryart.com to introduce his work. Frank used to joke, “It’s nothing, just the mathematical secret of the universe.”

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