First Results from the Large Hardon Collider

Posted on December 10, 2012 by woit

There’s a conference in Bad Honnef going on now entitled First Results from the LHC, with a website that carries two different interpretations of what “LHC” stands for (see the screenshot below):
First Results from the LHC

The talks are here. Yesterday CERN DG Rolf Heuer gave a summary talk about The Terascale after 2 years of LHC. Tomorrow some SUSY enthusiasts will be summarizing their view of the current situation, with John Ellis scheduled to talk on “What is it? What else? What next?”.

In other news, I’m hearing rumors of a big announcement tomorrow at CERN. The rumor is that Yuri Milner has decided that not all prizes should go to theorists, and that the Nobel committee not awarding prizes for the Higgs discovery is something that he can help fix. We’ll see tomorrow if this pans out…

Posted in Experimental HEP News | 6 Comments

This Week’s Hype

Posted on December 10, 2012 by woit

Space.com has a new story entitled Space Bursts Provide Insight to Theory of Everything, which has been picked up elsewhere as “evidence for string theory”. For instance Physicists Find New Evidence Of A ‘Theory Of Everything’ In The Wreckage Of Dead Stars tells us:

Physicists studying the rotation of minuscule particles fired by exploding stars light years from Earth have found new evidence for a so-called ‘Theory of Everything’.

Researchers have been frantically studying ways to reconcile two apparently contradictory pillars of modern physics for decades.

Put simply, those are Einstein’s theory of relativity – which covers the interaction of space and time on a large scale – and quantum theory, which covers the strange ways that sub-atomic particles behave.

One of the ideas mooted as a possible explanation is string theory, a framework which proposes that all of matter is made up of loops of vibrating strings…

What is relevant for this story is the proposal in superstring theory that every particle of matter has an equal and opposite ‘anti-matter’ particle, which if time were reversed would behave in exactly the same way as normal matter.

And it is this that new observations by the Japanese Aerospace Exploration Agency’s Ikaros spacecraft could help reinforce…

Using their Gamma-Ray Burst Polarimeter, the scientists are studying how those particles rotate. If the rotation of their polarity had changed even slightly, it would indicate a lack of symmetry if time were reversed – thus evidence against superstring thory.

And, luckily, the reported conclusion is that no change was detected. The team said that they are confident to one part in 10 million that the symmetry is consistent – a new record.

So the idea seems to be that CPT symmetry is evidence for string theory. Kind of like how it has become popular to claim observations being consistent with quantum mechanics as “predictions of string theory”.

The Space.com story seems very confused: string theory predicts no CPT violation, but finding evidence for it would support string theory:

The findings could have implications for superstring theory — the idea that all fundamental particles are actually loops of vibrating string — which is one attempt to unify nature’s forces and create a theory of everything. If the idea is right, it would help reconcile two contradictory theories: Einstein’s general relativity, which describes things that are very big, like gravity, and quantum mechanics, which describes the realm of the very small…

Superstring theory scientists predict that if particles and anti-particles (antimatter is an opposite form of normal matter) traded places and time was reversed, the world would still look the same. If any evidence is uncovered that matter and antimatter actually act differently, or violate their apparent symmetry, it could offer support for superstring theory.

They also link to a new story about 5 reasons we may live in a Multiverse.

What’s generating these stories is this press release from the University of Tokyo, based on PRL acceptance of this paper. It’s about an interesting test of CPT invariance, but bringing string theory into it is bizarre, and even the authors aren’t clear about whether string theory says CPT or no CPT. From the paper:

Lorentz invariance is the fundamental symmetry of Einstein’s theory of relativity. However, in quantum gravity such as superstring theory [1], loop quantum gravity [2] and Horava-Lifshitz gravity [3], Lorentz invariance may be broken either spontaneously or explicitly. Dark energy, if it is a rolling scalar field, may also break Lorentz invariance spontaneously. In the absence of Lorentz invariance, the CPT theorem in quantum field theory does not hold, and thus CPT invariance, if needed, should be imposed as an additional assumption. Hence, tests of Lorentz invariance and those of CPT invariance can independently deepen our understanding of the nature of spacetime.

and the press release:

Some quantum gravity theories, trying to unify Einstein’s theory of relativity with quantum mechanics, (e.g., superstring theory) predict that structures of space-time at extremely short distances may be totally different from what we think we know. On the scales treated by terrestrial experiments, the world looks exactly the same as its mirror image if the roles of particles and anti-particles are exchanged and the direction of time is reversed (i.e., CPT symmetry is conserved). If this symmetry is broken at extremely short distances, as predicted in some quantum gravity theories, polarization of photons from distant celestial objects would rotate during its long journey to us.

I was starting to get more optimistic that the days of nonsensical “tests of string theory” might be over, but it looks like this phenomenon is here to stay.

Update: Scientific American has the same story, headed with:

Gamma rays emitted during the formation of neutron stars and black holes allow scientists to study fundamental principles like superstring theory

Posted in This Week's Hype | 2 Comments

Decay: The LHC Zombie Film

Posted on December 8, 2012 by woit

Today is the release date for the film Decay, described as “a zombie film made and set at the LHC, by physics PhD students”. It’s available for download here, on Youtube here.

The plot is summarized as

The film follows a small group of students (played by physicists) after a disastrous malfunction in the world’s biggest particle accelerator. As they try desperately to escape from the underground maintenance tunnels, they are hunted by the remains of a maintenance team, who have become less than human.

It’s quite professionally done, on a remarkably low budget of about $3000, and of course the science is way, way better than usual for a Hollywood film. Highly recommended. Note that

This film has not been authorized or endorsed by CERN

For something more reality-based, try the latest episode of Colliding Particles, entitled “Blogs”, which features Philip Gibbs and his role in blogging the Higgs and putting together unofficial combinations of results. Not Even Wrong puts in a cameo appearance in the background…

Posted in Film Reviews | 7 Comments

Forty Years of String Theory

Posted on December 5, 2012 by woit

The journal Foundations of Physics has been promising a special issue on “Forty Years of String Theory: Reflecting on the Foundations” for quite a while now, with a contribution first appearing back when it really was 40 years since the beginnings (more like 43 now). The final contribution has now appeared, an introductory essay by the editors (’t Hooft, Erik Verlinde, Sebastian de Haro and Dennis Dieks).

The overall tone of the collection is one of defensive promotion of the subject. The fact that string theory’s massively overhyped claims to give a unified theory of particle physics have led to miserable failure is mostly completely ignored. From the introductory essay one would never guess that string theory was ever supposed to have something to do with explaining the Standard Model of particle physics and that there were hopes that it would find some sort of vindication at the LHC, perhaps via the discovery of SUSY (the LHC is not even mentioned in this essay). String theory is presented purely as a theory of quantum gravity that has led to new insights in mathematics and had various other applications through the dualities it has uncovered. It’s main shortcoming is described as

the lack of directly testable experimental predictions that would signal ‘string physics’

which seems to me intentionally misleading, implying that string theory makes indirectly testable predictions. The problem with string theory is that it makes no predictions about anything, not that it only makes indirectly testable ones.

Three of the eleven articles in the collection are described as representing critics of string theory. The first, from Carlo Rovelli, does do a good job of explaining many of the problems of string theory. Lee Smolin’s contribution is not much about string theory, but more an examination of the general issue of the “Landscape problem”, comparing a range of different theories in which the laws of physics are different outside our observable universe.

’t Hooft’s On the Foundations of Superstring theory calls for more attention to the lack of any fundamental description that tells us what string theory really “is”, taking the point of view:

we conjecture that the “true theory” is something totally different from superstring theory (and certainly also different from gravitating quantum field theories), but that string theory may approximate the truth to various degrees of accuracy in one or several of its compactified realizations, just as it does for some condensed matter systems and QCD.

He ends with an argument (which he notes is “one where only few readers will follow me”) that one problem with string theory is that it uses the conventional quantum formalism, which he feels is flawed, needing replacement by an “emergent” version of quantum mechanics. For more about the sort of thing he has in mind, see here.

Two articles by philosophers of science, Dean Rickles and Richard Dawid address the question of how to evaluate a supposedly scientific theory that, like string theory, makes no experimentally testable predictions. Both pieces seem to me to suffer from a rather uncritical attitude towards various forms of string theory hype. For Rickles, the dominance of string theory can be justified by its “mathematical fertility”, for Dawid the justification is “the assessment of scientific underdetermination” (roughly, there aren’t any other good ideas). That it has led to some interesting mathematics and that there’s not a lot of good alternative ideas out there are perhaps the two best arguments for pursuing string theory, but in both cases the situation is far more complicated than string theory advocates would have one believe.

The articles by string theorists (Balasubramanian, Giddings, Gubser. Martinec, Susskind and Duff) have a range of interesting things to say, sometimes amidst large dollops of string theory hype. Almost all evade serious discussion of string theory’s failure to say anything about the Standard Model (although Susskind argues, a la Multiverse, that this a positive feature of string theory). Giddings perhaps makes the most serious criticism of string theory in the entire volume, discussing its problems as a theory of quantum gravity, where other authors see a big success and the theory’s main selling point.

The article by Duff is by far the most bizarre thing in the volume, and I wrote about it extensively a year ago here. As Duff sees it, the problem is just that critics of string theory are misguided and misinformed. He includes a three page denunciation of Garrett Lisi which has nothing to do with string theory, characterizes the major recent research directions in string theory as fluid mechanics and the black hole/qubit correspondence, and has an appendix about the press release Imperial College put out making absurd claims that he had finally figured out how to make predictions from string theory (see here). The editors of the volume seem to be rather defensive about publishing such a thing, noting

Needless to say that the opinions expressed in this paper are entirely the author’s own and that it is not our intent to spark new popular or otherwise heated discussions.

but justifying it as

we are happy to include this paper in our special issue as addressing questions that are important not only to scientists but also to the wider public, which was among our initial intents.

and ending with

We warmly recommend Duff’s very readable and playful contribution.

Nothing about Duff’s piece struck me as “playful”, but that the editors see it as some sort of joke would explain why they thought it worth publishing.

Update: Over at The Browser, Steven Gubser recommends that people should read The Elegant Universe and four string theory textbooks. Asked about the “no predictions problem”, Gubser does his best to mislead, claiming the situation is just like that with QED that Feynman got the Nobel Prize for. As for SUSY, if the LHC finds it, that’s evidence for string theory, if not, no problem. There’s the old favorite “the LHC might produce microscopic black holes”. About whether string theory makes testable predictions about the heavy ion physics the LHC is studying

String theory might predict that such and such number is one, and the experiment might say well it’s about two, but it could instead be one. That’s the kind of accuracy with which things can typically be done.

Posted in Uncategorized | 31 Comments

News from CERN

Posted on December 5, 2012 by woit

Very light posting recently, partly due to being busy keeping up with my class, but more due to just not noticing anything particularly newsworthy. Matt and Lubos have quite a lot to say about Time magazine’s not describing the Higgs mechanism accurately, but I find it hard to get too excited about that, with my sympathies lying with any poor journalist given the impossible task of explaining this in a few words to the public.

Today at CERN there’s an LHCC meeting, with status reports on the machine and the experiments available here. The 8 TeV proton-proton physics run has just about ended, with the next week or so to be devoted not to luminosity production, but to machine studies. The integrated luminosity for the run will be about 23 inverse femtobarns, significantly above the original plan for the year. A heavy-ion run will end in February, after which the machine will be shut down for a long period in order to fix the magnet interconnects and other problems, to allow running at or close to the design energy of 7 TeV/beam. The current plan has proton-proton physics at 6.5 TeV/beam starting again about April 2015.

It seems likely that there will be no new results about the Higgs until the Moriond conference in March. CMS and ATLAS will then have quite a while to work on doing the best possible analysis of their 7 and 8 TeV data for information about the Higgs. From now on, attention will focus on what CMS and ATLAS have to say about the signal sizes in the various channels where the Higgs is supposed to show up, as well as theoretical studies of how possible next generation accelerators would perform in terms of doing better at these measurements than the LHC. The LHC Higgs Cross Section working group is meeting today and tomorrow on this topic, talks are available here. Next week the KITP will host a similar workshop.

The continuing big story from the LHC is that of no SUSY or other BSM physics showing up. The LHCC ATLAS slides have

Physics beyond the SM did not show up yet. There is no need for preliminary conclusions. Let’s continue our work and look were we haven’t looked so far.

but theorists are definitely starting to draw preliminary conclusions, needed or not. At Scientific American, Glenn Starkman has a piece entitled At CERN: Down in the Mouth in Paradise which paints a sorry picture of the situation caused by SUSY not showing herself:

The Standard Model is absurdly fine-tuned, we were told – balanced on a knife-edge off which it has no right not to tumble. It has an un-natural hierarchy of scales. It has too many free parameters, and some of them are very, very small. Why, the electron mass is less than 0.00001 times the weak scale (the energy scale governing weak interactions such as the W and Z boson masses), which is itself 10-17 (that 0.0000000000000001) times the Planck scale (the energy scale governing gravity)! And speaking of gravity, the Standard Model can’t accommodate quantum gravity. We need Low-Energy Supersymmetry, or Technicolor, or Large Extra Dimensions, or … One of these MUST be found at the LHC!

Forty years of theoretical work has been based on these expectations. Papers with thousands of citations have been written. Courses taught. Textbooks published.

Prizes awarded! Illustrious careers navigated! And yet despite all this build up of theoretical expectations, there is no experimental hint of anything outside the Standard Model at the LHC. Hence the long faces and worried words wherever theorists gather to drink coffee. Hence the disappointment in the eyes of the young experimentalists looking forward to the next accelerator, the next frontier where their mark will be made…

Walk the halls, go to theory seminars, have lunch with a theorist, or an ambitious young experimentalist. Look for the classic symptoms of grief.

Denial. Vigorous debates about whether the fact that the dog did not bark in the night suggests that it is a Chihuahua or a Rottweiler. My friends – at some point if there is no barking, we must conclude there is no dog.

Anger. At those of us “misguided” enough to doubt the imminence or even the necessity of Beyond the Standard Model physics.

Bargaining. Perhaps BSM physics has not been discovered because we’ve been demanding too much explanatory power from science. If we just relax our expectations for the predictivity of science, and introduce a multitude of universes in which we occupy a particular one best suited to our existence, then we can let our extensions to the Standard Model be un-natural, many of their properties unpredictable, and explain why they haven’t been discovered yet!

Depression…

We’re not ready for Acceptance! At least, sitting here listening to the LHC hum, I can still hope.

Posted in Experimental HEP News | 9 Comments

Assorted Links

Posted on November 23, 2012 by woit
  • Paul Frampton has been found guilty on drug charges in Buenos Aires, looks like he will be able to serve out his sentence under house arrest, get released sometime in 2014. It’s unclear at this point how the University of North Carolina will handle this. For details, there’s Physics World, the Daily Mail, the Winston-Salem Journal, and Clarin.
  • Erik Verlinde over the past couple years has gotten 6.5 million euros in prizes and grants to fund his work on entropic gravity (see here). Now, he’ll head up a new institution, the Delta Institute for Theoretical Physics, funded with 18.3 million euros from the Dutch scientific funding agency NWO as part of its Gravitation Programme.
    There’s an interview with Verlinde here. He says he’s working on explaining dark matter with his entropic gravity ideas. There’s no paper about this, I guess because:

    There are some small gaps in my reasoning and things that I still do based on intuition. I’m trying to fill in those gaps.

    but he thinks these ideas about dark matter will be tested in “no more than 10 or 15 years”.

  • Another new theoretical physics institution is The Higgs Centre for Theoretical Physics in Edinburgh, where they’re hosting an inaugural symposium in January.
  • The latest TEDYouth is online, see here. It seems that they may think that Youth these days is pretty ADD, since they have all presentations limited to six minutes. In one of them (around 3:50) they’ve got Clifford Johnson explaining the exciting new idea of replacing particles by strings moving in extra dimensions.
  • Mochizuki’s claimed proof of the ABC Conjecture still seems to be resisting the attempts of experts to understand and evaluate it. He has put on his web-site some slides for a talk next month, and promises a survey article next March.
  • Easier to follow in principle, but at 367 pages still pretty daunting, is a new paper from Laurent Lafforgue, chronicling his attempt to develop “non-linear” versions of the Poisson formula that would imply Langlands functoriality.
  • If you were wondering about that tatoo in Edward Frenkel’s film, see Mathematics, Love and Tattoos for an explanation.
  • In other film news, there’s the Colliding Particles project for a film about the Higgs. They’ve got a new segment up, several more coming soon at one/week.
  • The debate in the HEP community about the death of SUSY goes on, and will undoubtedly continue along the same lines for quite a while. Latest is from New Scientist, which has Steven Weinberg describing the situation in a way that that can’t be argued with:

    SUSY’s plausibility is reduced, but not to zero.

    For the argument over whether SUSY was and is an overhyped, implausible idea, on one side there’s Michael Peskin, with:

    I think that the serious effort given to SUSY is appropriate…”

    and on the other, taking the Not Even Wrong side of this argument, there’s Matt Strassler with:

    The theory, specifically as something we would observe at the LHC, was wildly over-promoted.

Update: One more. A Science magazine article about the problem with “Open Access” journals discussed here. According to Science:

Meanwhile, the OA industry is becoming increasingly diverse; it includes traditional powerhouses, such as Germany’s Springer, which now publishes about 300 OA titles, as well as a vast array of newcomers. OA publishers have a built-in incentive to lower the bar, Dupuis says, because in contrast to subscription journals, an OA title earns more revenue with every paper its editors accept.

Moreover, many so-called predatory publishers—which often eschew peer review, use fake editors, or contain plagiarized papers—have flooded the market, says Jeffrey Beall, a librarian at the University of Colorado, Denver, who keeps an online list of these dodgy outfits.

Posted in Uncategorized | 34 Comments

Scrutinizing the Cosmological Constant Problem

Posted on November 20, 2012 by woit

Normally I do my best to ignore claims to have figured out the vacuum energy problem. There’s an endless number of them, mostly looking pretty dubious, and the world is full of people much more expert on the subject than me, so it seems that my time would be better spent elsewhere. I did however just notice a new preprint making such claims, Scrutinizing the Cosmological Constant Problem and a possible resolution, by Denis Bernard and André LeClair, and am curious about it. Unlike most of such things, the authors seem to know what they are talking about, and the whole thing looks not implausible to my non-expert eye. Can an expert tell me what is wrong with this (or, alternatively, tell me and my blog readers that it’s a new good idea, or an old one that is not well known)?

Comments better be about the Bernard/LeClair paper and well-informed, or will be ruthlessly deleted.

Posted in Uncategorized | 26 Comments

Latest from Arkani-Hamed, Ellis and Gross

Posted on November 20, 2012 by woit

Three of the leading figures in HEP theory have today or recently spoken about their current view of SUSY in light of the negative LHC results, here’s a report:

  • At the IAS recently, Nima Arkani-Hamed spoke on The Inevitability of Physical Laws: Why the Higgs Has to Exist. Yuri Milner was in the audience, and I gather that this (and Maldacena’s recent similar talk) was intended to fulfill the promise of giving a public talk that came with their receipt of $3 million Fundamental Physics Prizes.

    Both Arkani-Hamed and Maldacena talked not about their own work, but about the Higgs, with Maldacena emphasizing the importance of gauge symmetry, Arkani-Hamed the constraints imposed by unitarity and Lorentz invariance. At the end of his talk, Arkani-Hamed gave a big advertisement for SUSY, with a new and somewhat bizarre argument I hadn’t heard before. He argued that since QM + special relativity imply that elementary particles must have spin 0,1/2,1,3/2,2, and until recently 0 and 3/2 were missing, the fact that 0 (the Higgs) has now been seen implies (by the “totalitarian principle” that everything that can happen must happen) that the next thing to be discovered will require a spin 3/2 particle and this needs SUSY. Of the various weak arguments put forward for SUSY, this seems to me to be the weakest yet.

  • At CERN today there was a 70th birthday celebration for Chris LLewellyn Smith. I didn’t watch John Ellis’s talk, but his slides are here. Evidently he argued that SUSY is not dead yet, pointing to the latest paper from the MasterCode collaboration. Their most recent CMSSM SUSY “predictions” have gluinos at either 2000 GeV (hard for the LHC to see at full energy after 2014) or 4000 GeV (impossible for the LHC ever to see).

    No mention was made of the similar pre-LHC predictions (see here and here) which had the Higgs at around 113 GeV, gluinos at 700 GeV or so, and squarks lighter than this, all of which have been shown to be radically mistaken. For some perspective on this on an even longer time scale, take a look at this 1984 survey article, Supersymmetry – spectroscopy of the future? : or of the present?. It gives much the same enthusiastic motivation for SUSY that we still get in all SUSY talks, with Ellis optimistic that the latest data had hints of SUSY with sparticle masses around 40 GeV (“nicely compatible” with the recent discovery of a 40 GeV top quark…).

  • Also speaking today was David Gross, and I did get a chance to watch his talk. He commented on Ellis’s claim that SUSY was not yet dead by noting “we see no signs of life either”, then went on to lay out two “extreme scenarios”. The pessimistic one would be nothing but the SM at LHC energies and no detection of dark matter. In that case, about SUSY he commented that it “could be that Nature does not take advantage of this”, which I think is the first time I’ve ever heard him raise this possibility. The optimistic scenario was the usual picture sold pre-LHC: detection of SUSY and dark matter, non-SM Higgs. Gross said that he’s an optimist, but gave no argument for the optimistic scenario beyond the one that it’s a good idea in life for a scientist to be an optimist.

Update: More at Nature about SUSY’s problems and quotes from its defenders.

Update: Over at the Simons Foundation web-site, there’s an excellent new article about the SUSY debate by Natalie Wolchover.

Posted in Uncategorized | 36 Comments

New Higgs Results

Posted on November 13, 2012 by woit

New results about the Higgs should appear over the next day or so, perhaps first here and here. First to appear is the CMS tau-tau result which is a signal strength of .72 +/- .52 the SM value.

Will update this posting with the results as they appear.

I guess the rumors were right: no update from ATLAS for gamma-gamma, they’re just presenting the earlier data: signal strength of 1.8 +/- .5 times the SM value. “Ambitious campaign underway to include a larger data-set.”

ATLAS WW channel signal strength is 1.5 +/- .6 times the SM value (see here). For some reason they are only using 2012 8 TeV data, not combining with the 7 TeV data.

Atlas tau-tau signal strength is .7 +/- .64 times the SM value (see here). Very similar to the CMS value. They are not yet sensitive to the bb channel, where the Tevatron has the advantage and has evidence of a signal.

Update: All new results are out now, but rather anti-climactic since neither CMS nor ATLAS is reporting new results for the channel with the strongest signal (gamma-gamma), where the signal strength may be anomalously high. ATLAS is also not reporting for the other high statistics channel (ZZ). CMS is, with signal strength .8 +.35/-.28 the SM value. They also claim to rule out (at 2.5 sigma) the hypothesis that this is a pseudoscalar rather than scalar. Everything reported is in line with the SM, but for the most interesting numbers we may have to wait until next March (Moriond).

For much more details about all this, see Tommaso Dorigo here and here, Matt Strassler here and here, Philip Gibbs here. For primary sources, CMS here, ATLAS here, presentations here.

Update: For another excellent source, see Jester, who has the scoop on why ATLAS and CMS didn’t update some channels:

It came to a point where the most exciting thing about the new Higgs release was what wasn’t there 🙂 It is difficult not to notice that the easy Higgs search channels, h→γγ and ATLAS h→ZZ→4l, were not updated. In ATLAS, the reason was the discrepancy between the Higgs masses measured in those 2 channels: the best fit mass came out 123.5 GeV in the h→ZZ→4l, and 126.5 GeV in the h→γγ channel. The difference is larger than the estimated mass resolution, therefore ATLAS decided to postpone the update in order to carefully investigate the problem. On the other hand in CMS, after unblinding the new analysis in the h→γγ channel, the signal strength went down by more than they were comfortable with; in particular the new results are not very consistent with what was presented on the 4th of July. Most likely, all these analyses will be released before the end of the year, after more cross-checking is done.

Update: Two interesting workshops on prospects for a Higgs factory are being held at Fermilab this week. See here for one that is on-going, see here for Tuesday’s one-day mini-workshop on prospects for a muon collider Higgs factory. I’d never seen much before about the idea of using a gamma-gamma collider to study the Higgs, curious if that’s really technologically viable.

Posted in Experimental HEP News | 20 Comments

SUSY in the Hospital?

Posted on November 13, 2012 by woit

HCP2012 Higgs results will be announced Wednesday (I’m hearing that CMS tau-tau signal is .7 +/- .5 x the SM value), but interest may focus much more on the strong SUSY exclusions being announced there. So far the LHCb result on B(s)->mu+mu- has been the one getting all the attention, with a BBC News story describing it as “a significant blow to the theory of physics known as supersymmetry”. In the story experimentalist Chris Parkes describes the current situation as “Supersymmetry may not be dead but these latest results have certainly put it into hospital.” John Ellis is having none of this though:

Supporters of supersymmetry, however, such as Prof John Ellis of King’s College London said that the observation is “quite consistent with supersymmetry”.

“In fact,” he said “(it) was actually expected in (some) supersymmetric models. I certainly won’t lose any sleep over the result.”

The story has been picked up by Slashdot, and the Register (which has Supersymmetry takes an arrow to the knee).

The bad news for SUSY out of Kyoto however does not end there. ATLAS and CMS are both coming out with new analyses using this year’s 8 TeV data which significantly expand previous limits on SUSY, getting close to ruling out popular last-ditch efforts to save the theory. For the latest, look at this HCP2012 page, this ongoing Chicago workshop, and CMS results announced here (like this), ATLAS results announced here.

The last ditch effort to save the idea that SUSY solves the so-called hierarchy problem goes under the name of “Natural Supersymmetry”. It involves moving most superpartners to high masses where the LHC can’t see them, keeping only the stop, sbottom, gluinos, and a couple neutralinos at LHC accessible masses. If you look at the bounds given on these masses for instance here, and compare to the latest LHC results, you’ll see that there’s trouble on all fronts for this idea, which is now very close to being essentially ruled out.

Gordon Kane is fighting back against the BBC by going to Lubos Motl’s blog to argue that the LHCb result is no problem for his string theory “predictions”. You see, his “prediction” is now that most superpartners are way beyond what the LHC can see, so not only is the LHCb result not negative for SUSY, but it “adds to the evidence for supersymmetry and for M/string theories”. Kane doesn’t mention any of the other SUSY excluding results coming out this week, or their implications for his “prediction” of the gluino mass. Last year Kane was telling Tommaso Dorigo

I and others expect this decay to tops and bottoms is the signature by which gluinos will be found, with masses well below a TeV

and his slides had a gluino mass prediction of about 600 GeV. Late last year he was arguing that the gluinos would be seen by this past summer. More recently, he’s modified the graph in his slides to move the gluino up to 1 TeV. This week ATLAS reports a new gluino mass limit of 1.24 TeV, so Kane will have to modify his slides yet again.

The combined effect of the bad press and the devastating experimental results on the 30 year old SUSY juggernaut will be interesting to follow. At this point, it is hard to see how one could rationally expect anything positive for SUSY to come out of further analyses of the 7 TeV and 8 TeV data. I suppose many will try and delay acknowledging failure by saying one must wait for the 13 TeV data, which we won’t see until 2015 or so, but I don’t think this is going to convince many people.

Update: Matt Strassler objects to the BBC article, on the grounds that one should not describe what is happening to SUSY in terms of “blows” or it getting hurt. Instead, one should stick to saying it is getting “cornered”, and he agrees that “the cornering of supersymmetry is well underway”. The question this raises though is what happens to SUSY once it is cornered if you object to it getting hurt. I suspect the hope of many SUSY theorists is that even once cornered, SUSY will continue to be well-treated, receiving annual $3 million prizes and being taught to new generations of graduate students.

Update: The Daily Mail covers this, with the non-tabloid-like headline Experts take conflicting opinions as to how far results support the theory of super symmetry. Oliver Buchmueller joins Gordon Kane in the bizarre game of claiming negative results as positive for SUSY, making the argument

‘This is another piece in the puzzle and with it the world appears even more SM-like,’ he said. ‘It supports SUSY, because that is the only theory that can include the Standard Model in a wider concept of New Physics.’

Update: More about this from Matt Strassler, who writes about Theory Killers at the HCP conference. I guess it’s still all right to kill “theories”, as long as SUSY herself doesn’t get hurt.

Update: The rather odd controversy over the BBC story goes on, with Lubos Motl and Matt Strassler continuing to argue that the scientific method implies that SUSY can’t get hurt. I would have thought that it was uncontroversial that if proponents of an idea claimed that it would be vindicated by an experiment, and the experimental result came back negative, that was not good for the idea, but, at least for SUSY, that doesn’t seem to be the case. Yes, SUSY comes in infinite varieties, many of them never testable, but the experimental results shooting down its versions sold as the most well-motivated ones do have implications for its health. I see no reason why one needs to wait for the LHC to examine every possible remote corner of parameter space that it can access before remarking on what has happened.

Update: It is being pointed out that the BBC story is inaccurate: the LHCb bounds on Bs meson decays that rule out a large chunk of SUSY theory space were already there in March. So, on this front SUSY entered the hospital in March, not this past week. Of course, an even bigger inaccuracy in the BBC story was describing SUSY as an idea that has only encountered serious health problems recently, rather than many years ago…

Update: There’s now a fourth rant from Matt Strassler about the LHCb result, a topic on which he has become a bit of a zealot. The point being made is that SUSY was already so badly injured pre-LHCb that they didn’t make things any worse. It’s quite possible he’s right about this, would be interesting to hear a response from the LHCb people.

Update: A characteristically lucid posting on the topic from Jester: BS and SUSY.

To conclude, you should interpret the LHCb measurement of the Bs→μμ branching fraction as a general, strong bound on theories on new physics coupled to leptons and, in a flavor violating way, to quarks. In the context of SUSY, however, there are far better reasons to believe her dead (flavor, CP, hierarchy problem, direct searches). So one should not view Bs→μμ as the SUSY killer, but as just another handful of earth upon the coffin 😉

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