String Theorists Throw SUSY Under the Bus

Over the past few days the results of the 2011 LHC run have been revealed at the EPS-HEP 2011 conference in Grenoble, where a press conference today marked the beginning of the next part of the conference, featuring summary talks. For some discussion of these results see for example here, here, here, here and here. The bottom line is much stronger results ruling out supersymmetry, extra dimensions, black holes and other exotica, restriction of the possible mass range of the Higgs to about 114-150 GeV, and a tantalizingly small and not yet statistically significant excess of possible Higgs events in the mass range 120-145 GeV.

The big surprise here is that the experiments have done a fantastic job of getting these analyses of the data done at record speed. Before the LHC turn-on, estimates based on experience at the Tevatron tended to be that it would be 2012 before we saw completed analyses of a significant amount of the 2011 data. A lot of people have been working long hours and going without a summer vacation… The bottom line though is not a surprise, but rather pretty much what many people (including myself) expected. The unconvincing popular theoretical models of the last few decades have finally been confronted with experiment, which is falsifying them, to the extent that they can be falsified. It’s an inspiring example of the scientific method working as it should. The remaining mass range for the Higgs is the expected one, and, as expected, this is the hardest place to separate the Higgs from the background. If it’s really there, the data collected during the rest of this year should be enough to give a statistically significant signal. So, within a few months we should finally have an answer to the question that has been plaguing the subject for decades: “Higgs or something else?”. This is very exciting.

For more than a quarter-century, supersymmetry has been advertised as the most significant prediction of string theory. Back in 1996 Gross and Witten responded to John Horgan’s skeptical take on string theory in The End of Science with an article in the Wall Street Journal where they claimed:

There is a high probability that supersymmetry, if it plays the role physicists suspect, will be confirmed in the next decade. The existing accelerators that have a chance of doing so are the proton collider at the Department of Energy’s Fermi Lab in Batavia, Ill., and the electron collider at the European Center for Nuclear Research (CERN) in Geneva. Last year’s final run at Fermi Lab, during which the top quark was discovered, gave tantalizing hints of supersymmetry. The situation should be clarified when this machine is upgraded in 1999. (A further upgrade, which would cost the Department of Energy about $300 million, should be seriously considered.) As for the CERN electron collider, its energy is being increased by 35% in the next few months. The results could be dramatic, since electron colliders, though their energy is generally much lower than that of proton colliders, are rather thorough and swift in exploring certain phenomena.

If supersymmetry is out of reach of these existing colliders then it is very likely to be discovered at the Large Hadron Collider, which will begin operation at CERN in about a decade…

Wherever it occurs, the confirmation of supersymmetry would open up one of the golden ages of experimental physics. It could provide us with essential insights about the unification of the four major forces; that is, a theory that would describe gravity, the strong nuclear force, the weak atomic force and the electromagnetic force as varying expressions of a single phenomenon. And it would give a big boost to the development of a remarkably rich new theoretical framework known as string theory. For supersymmetry is one of the basic predications of string theory.

The next year Physics Today published Gordon Kane’s String Theory is Testable, Even Supertestable, which included a plot showing gluinos and squarks as having expected masses in the range of 200-300 GeV (the latest results rule them out in typical SUSY models up to about 1000 GeV).

Today, the most prominent active string theory bloggers have blog entries reacting to the weekend’s news. Clifford Johnson has Living in Interesting Times, where he writes:

One of those hoped for stories is called Supersymmetry, which would imply the existence of several more particles besides just the Higgs. Now, the cool thing is that the simplest models of supersymmetry could be in danger as well if we do not see something in the coming several months. Wouldn’t it be interesting if both the Standard Model Higgs and the simplest models of Supersymmetry were ruled out? (I’m not saying that they are – it’s all to soon to tell – but it is a possible outcome.)

When the LHC turned on, Lubos Motl was blogging about Why supersymmetry should be seen at the Large Hadron Collider, giving the probability of the LHC seeing SUSY as “90% or higher”. After the results of the last few days, he’s done a 180 degree turn, with a new blog entry attacking phenomenologists and arguing that the LHC results just show that HEP theorists should be doing string theory, not phenomenology:

No hep-th theorist has ever claimed or boasted that the bulk of his work had too much in common with the data produced by the next-generation collider so of course, the hep-th work isn’t really affected by the “null” results from the LHC. Many theorists and many string theorists – but not all – would feel more excited if the LHC were generating totally new phenomena and their phenomenological friends would be really thrilled. However, it’s still true that the theorists don’t care as much as the phenomenologists do.

What I really want to say is that most of the phenomenological work has been a waste of human resources and time. Instead of producing 1,000 models that could be relevant for the sub-TeV observations, those people could have just waited for a few years and let Nature speak. And it seems that Nature has spoken – and it may still speak in an ever clearer language – and so far, the answer is that the right model of these phenomena is called the Standard Model…

So I hope that instead of shifting the energy scales from 200 GeV to 1,400 GeV and continuing in random guessing, many phenomenologists will buy some string theory textbooks and begin to think about the Universe at a slightly deeper and less sensationalist level.

Update: Lubos clarifies here: he’s only throwing some SUSY models under the bus, not all of them. It’s no longer above 90%, but he still thinks there’s a 50% chance that the LHC will see supersymmetry. And all the bogus claims for “tests of string theory” are my fault, since I created a hostile environment for string theorists where they felt they had to do this kind of thing.

Update: The MasterCode Project has moved up to higher masses its “best-fit” points for SUSY now that 2011 LHC results have ruled out previous “best-fit” points, see here. Now the “best-fit” for SUSY is not even a very good fit… Tommaso Dorigo explains and comments here.

Update: In his talk concluding the conference, David Gross throws just the CMSSM under the bus, saying it is now “on life support”. He argues though that this is just one possible SUSY model, and one can’t conclude much from the death of the CMSSM. Much of his talk was an advertisement for N=4 SSYM and AdS/CFT. He’s sticking to his prediction of last year that SUSY particles will appear within 10 years, no word on when he’ll give up if the LHC continues to see nothing. Near the bottom of his list of predictions was “string theory will start to be a THEORY, with predictions”, which drew laughter from the crowd. He acknowledged that it was next to last on a list ordered by plausibility, but insisted “Some day…”

Update: Pauline Gagnon reports on what theorists are up to in response to all this:

This summer, I had the opportunity to spend a week at a theory workshop. Being the only experimentalist there, I spent plenty of time discussing what was going on in their camp. Clearly, they are not sitting idle while we are frantically searching our recently collected data for signs of new physics or the Higgs boson. On the contrary, many of them were already hard at work trying to find excuses for supersymmetry and reasons why it has not shown up yet as anticipated.

At Cosmic Variance John Conway summarizes the situation, and draws flak from Matt Strassler, who explains more here, and has a new paper out about how to evade the LHC results:

This is a key job of particle theorists; make sure all the ground gets covered by the experimentalists before they give up and move on!

Given the huge number of possibilities and parameters for how to implement SUSY, insisting that all of it gets tested by experiment will ensure that SUSY phenomenology will be with us for a very long time. Ideas like SUSY can never be completely ruled out, they can just be made so unlikely that they’re not worth people’s time anymore, and the argument over how much more unlikely the LHC results make SUSY will continue…

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75 Responses to String Theorists Throw SUSY Under the Bus

  1. chris bolger says:

    If supersymmetry is not found, what is the best explanation of the running of the coupling constants meeting precisely at the GUT level, as found in the early 90’s, in its absense?

  2. Peter Woit says:

    Chris,

    They don’t actually meet “precisely”, although the agreement is better than in the non-SUSY SM. The relative strengths of the SM couplings is just something we fundamentally don’t understand. GUT explanations haven’t worked out well, with their generic observable prediction (proton decay) not being observed. Note that to believe the SUSY GUT calculation of meeting of couplings, you have to believe that there is no physics affecting their running, from 1 TeV scale up to the GUT scale (the “desert hypothesis”). Most physicists have always found this difficult to accept.

  3. John Baez says:

    I’ve never believed supersymmetry was true in our universe. Earlier this spring I won a case of scotch from the particle physicist Dave Ring, on an old bet about whether the LHC would see “strong evidence for supersymmetry” after one year of operation.

    A true gentleman, he sent me an email saying “I believe I owe you a case of scotch. I knew they’d go over schedule at the LHC, but not by this much!” And he even got me 18-year-old Laphroaig.

    I would feel guilty if I won on a technicality. So, I’m glad they’re not seeing evidence of supersymmetry.

  4. Eric says:

    Might it be pointed out that the remaining low-energy range (115-135 GeV) allowed is precisely where the Higgs should be if TeV-scale SUSY exists?

    Furthermore, the energy range above 450 GeV is still allowed, which is where the Higgs should be if there turns out to be a heavy fourth generation.

  5. neo says:

    I am confused. I read elsewhere that at Higgs found between 115-140 GeV could be a SM Higgs or a SUSY Higgs. Why do you think the current range is ruling out SUSY?

  6. Alex says:

    Dang! I should have placed bets with Laphroaig. But wait! there is still time!
    Who is willing to bet a bottle of Laphroaig against the idea that there are particles that look like color-charged superpartners between 1200 and 1500 GeV? 🙂

    neo,

    Such a light Higgs is not only compatible with the SUSY, it is almost a necessity to have a Higgs in this region unless you add further stuff like a fourth generation, or make the superpartners very very heavy, to pull up the higgs using large loop corrections. Many models of SUSY being ruled out is simply for the lack of a signal in the usual SUSY discovery channels, like jets or leptons with missing energy (For R-Parity conserving SUSY), or corresponding observables for R-Parity violating SUSY.

    Eric,
    “which is where the Higgs should be if there turns out to be a heavy fourth generation.”
    Not too long ago, a standard fourth generation could maybe barely hide there, the trouble is that this would not only generically predict a heavy higgs, but also a production cross section that is a factor 5-9 higher than the SM one, because all of those new particles contribute to the coupling of gluons to the higgs. The ways to circumvent that is 1) to have a fourth generation and a fourth antigeneration, which would not have to talk to the higgs to be massive. But that’s not really a proper fourth generation, or 2) Have the higgs decay invisibly, which is of course not very compelling if only done for that reason.

    chris bolger,

    Making the couplings kind of meet without SUSY is possible by adding further fields, like for example a handful of scalar doublets. But then if you really postulate some kind of GUT at the resulting unification scale, you have to engineer away proton decay, and the hierarchy problem really shows up explicitely in your theory then because you have introduced explicitely a very high scale which turns up in the radiative corrections to the Higgs potential.

  7. Peter Woit says:

    neo,

    The Higgs results don’t rule out SUSY. What is causing trouble for SUSY is separate searches for strongly interacting superpartners which have turned up nothing.

  8. DB says:

    “a tantalizingly small and not yet statistically significant excess of possible Higgs events in the mass range 120-145 GeV.”

    In the hands of idiot journalists, this becomes
    “Scientists in the US announced they may have detected the elusive and potentially universe-changing Higgs boson particle yesterday, just two days after rivals in Switzerland signalled that they, too, have caught their first sight of it. “

    The Independent is considered to be a quality UK newspaper.

  9. Peter Woit says:

    DB,

    As usual, in this case it’s not only journalists who are to blame, see

    http://blogs.nature.com/news/2011/07/hep2011_a_whiff_of_higgs_at_th.html

  10. Peter Woit says:

    For a more problematic journalistic take on the situation, see

    http://www.newscientist.com/article/dn20729-should-we-worry-about-what-the-lhc-is-not-finding.html

    where we learn that:

    “there is no sign yet of gravitons – particles that transmit gravity and are essential for a quantum theory of the force – below an energy of 2 TeV”

  11. Alex says:

    “For a more problematic journalistic take on the situation, see”

    Apart from giving Supersymmetry, which you dislike, a prominent position and attributing it a tiny bit more than it can actually do for us, I thought it’s not that terrible an article. The 2 TeV Graviton, that obviously came out of a mingled statement about Randall Sundrum I suppose. I’ve seen much worse in official LHC public relations, like the whole recreating the big bang business…

  12. lun says:

    I think one needs to be careful about confusing “string theorists” with famous bloggers who write on string theory and more or less accepted spokespeople of the string theory community.

    Some string theorists have “trown supersymmetry under the bus” well before the LHC gave them a reason to do so:
    http://arxiv.org/abs/0804.4718
    http://arxiv.org/abs/hep-ph/0104274
    while these papers were ignored by bloggers and the scientific press, this does not necessarily make them invalid. This, in fact, illustrates one of the main problems of the way string research is done: The extreme faddishness of the field.

  13. David Bailey says:

    Given the colossal pressure on CERN to come up with some results, can we be 100% certain that they would not fudge the evidence for the Higgs?

  14. Peter Woit says:

    David,

    It’s not even clear which way you would want to fudge this. If they find the Higgs, they have an important discovery to crow about. If they rule out the Higgs, that’s an equally important (and much more interesting…) discovery.

    Remember that there are two major independent experiments looking for the Higgs. Each one of them is under a lot of pressure to not only make a discovery, but get it right. If they don’t get it right, their competition is sure to take advantage of this. Also remember that there are 3000+ physicists on each experiment. If some subset of them tried to fake the most important result they were looking for, their colleagues would not stand for it. Getting 3000+ physicists to agree to anything is nearly impossible, much less getting them to agree to a faked result.

  15. Alex says:

    @David Bailey,
    It’s not CERN’s job to analyze any data. They just provide the bang for the buck so to speak. Two collaborations of thousands of people who run the two main Higgs search experiments independently, do that. That does not mean that the people doing the analysis for the collaborations didn’t put some prejudice in these early results about our indirect expectations of a light Higgs, but that will quickly fade away with more statistics. You can be certain that, barring a sheer criminial conspiracy, an eventual Higgs discovery claim will be held under great scrutiny by a large number of people.

  16. Yatima says:

    I sure am glad that Lubos is an outlier. This mindset is appalling, tending towards occultism. A lifetime study of Kabbalistic texts can’t be far away.

  17. anonymous says:

    People have realized that string theorists are out of touch with reality, as evidenced by the near-absence of string theorists in this year’s Particle Rumor Mill.
    The LHC might soon prove that “phenomenologists” are out of touch with reality as well, as their models get decimated.
    How about we simply disband the whole hep enterprise? 30 years ago smart people already knew that particle physics was a dying field.

  18. Bee says:

    I’d agree that “Instead of producing 1,000 models that could be relevant for the sub-TeV observations, those people” SHOULD “have just waited for a few years and let Nature speak.” (Funny enough, I’ve said almost exactly the same in my talks during the last years to explain why I stopped working on models with large extra dimensions 6 years back…) But whether they COULD have waited is a different question. I believe I’ve commented here several times saying that this trend towards phenomenology seems unreasonable to me because many of the models are very poorly motivated (if motivated at all). And I say that as a phenomenologist myself. So why the paper flood? I guess the reason is simply too many people, too few jobs, pressure to publish and then in the late 90s everybody started yelling ‘falsifiability’ which did the rest. It doesn’t really matter which way you shove scientists, it always has a backlash. However, since that is unlikely to change anytime soon the question is now where will the next bubble be? I actually think we already see it coming, and it will be in cosmology.

  19. Neil Harris says:

    I don’t understand why Lubos Motl has to be so rude about Peter Woit, but then I’m southern English.
    This quote from Motl is worrying: “No hep-th theorist has ever claimed or boasted that the bulk of his work had too much in common with the data produced by the next-generation collider so of course, the hep-th work isn’t really affected by the “null” results from the LHC.” It begs the question: what experimental evidence does affect hep-th work?
    It cannot have escaped the notice of all physicists that the world seems to be running out of money (next week, in the case of the US federal government). It may be that the CERN LHC is the last particle collider, or that any successor will be a long way into the future. This has implications for experimental and theoretical physicists. There again, if experimental evidence is irrelevant to theorists like Motl, he’ll be able to carry on.
    As a mere science documentary film-maker I cannot contribute at a technical level, though I was honoured to film an interview with Peter Higgs back in 1995. He’s a charming, modest man and strove mightily to explain a difficult subject to a general audience. I am crossing my fingers for his sake that the LHC will resolve some of the theoretical predictions made by him and others getting on for nearly 50 years ago. I know he at least respects experimental evidence.

  20. rhofmann says:

    Like Neil Harris I also would like to thank Peter Woit for his constant efforts in exposing the desolate state of a failed research program in high-energy particle theory in spite of humiliation and aggressive action by some of its followers. It takes a presently rare-to-find strength of character, intelligence, conviction, wit, and integrity to stand as solid as Peter did over the last seven or so years.

  21. chris says:

    i don’t quite get it why Motls opinion is still discussed. he is out of the business for several years now and it shows in all his comments.

  22. Arun says:

    …resulting in the Superbus!
    http://www.superbusproject.com/

  23. CM Theorist says:

    Firstly, Motls’ opinion….I agree…who gives a crap. He’s just a typical internet blowhard trying to maintain some reputation of expertise by constantly giving his un-asked-for opinion.

    Regarding the coupling constants meeting at the GUT level? My problem with this has always been that one has to be confident in a linear extrapolation of many many many orders of magnitude. This sort of extrapolation almost never works. It is tantalizing…don’t get me wrong…but it’s completely absurd to take as some sort of evidence for supersymmetry.

  24. Peter Woit says:

    rhofmann,

    Thanks, but being witty and staying amused by it all is made very easy by Lubos.

    Actually I agree a bit with the point made by him and Bee that the emphasis on “phenomenology” in recent years is not necessarily healthy. The subject needs a good balance between phenomenology and formal theory. The dominance of formal theory by a failed research program, whose proponents refuse to admit this failure, is what has caused the rest of the community to lose patience. The multiverse nonsense and the spectacle of string-theory fanaticism that Lubos is the poster-boy for haven’t helped. If you’re going to work on ideas that aren’t ready for experimental test, you have to be honest with yourself when they aren’t working out.

  25. Phenner says:

    It should be pointed out that “phenomenology” is much wider than the caricature being portrayed here. The field involves a lot of SM (especially QCD) predictions, vital for separating new physics from backgrounds at the LHC. All the simulation programs – Pythia, Herwig, Sherpa etc – are written by phenomenologists. Deciding which observables can give the best chance to discover physics (i.e. where to look, what to plot, how to interpret it) is also part of this field. It’s true there are a lot of papers, especially recently, which make spurious attempts to explain ~2sigma deviations in terms of fanciful models, but I don’t see this as representative.

  26. Pingback: LHC treibt Higgs, Supersymmetrie & Co. in die Enge « Skyweek Zwei Punkt Null

  27. Yousuf says:

    If SUSY, and by implication Superstring Theory are going down the toilet, then what’s the next best theory down the line that needs to be falsified? Technicolor? Loop Quantum Gravity? Etc.?

  28. Peter Woit says:

    Yousuf,

    Superstring theory can’t really be falsified since it doesn’t predict anything. In particular, it doesn’t predict SUSY at LHC energies.

    The LHC will have nothing to say about LQG. It should have something to say about technicolor, which won’t survive if a Standard Model Higgs is found.

    So far, the LHC is finding nothing that disagrees with the Standard Model, already falsifying various models of extra dimensions, low energy strings, and much much more. If this continues, ALL models that make predictions about LHC scale physics different than the SM will be falsified.

  29. abbyyorker says:

    Maybe a little too celebratory here. SUSY is an appealing theory for many reasons and I am personally sad that there’s no evidence for it. It looks like LHC is decisively showing that the popular versions of SUSY are not correct in their details. But I secretly suspect that those versions were tilted towards those with low energy predictions, to take advantage of the presence of the LHC. So, as many have said, SUSY will never go away because it cannot be disproved, and un-disproved versions will likely be promoted and will sound good to many.
    My guess is that people will soon become unable to do high energy physics, because of the expense, unless there is some astonishing breakthrough in the method.

  30. Yousuf says:

    Peter, if even a Standard Model Higgs isn’t found amongst all of the noise of the range of energies that they are now looking for at LHC, then is the Higgs dead, or do they continue looking for it at ever higher energy ranges? Also if SM Higgs isn’t found, then does Technicolor then automatically get promoted into the Standard Model in its place? I.e. if there’s no Higgs then it’s Technicolor, or if there is Higgs then there’s no Technicolor.

  31. Justin Hilburn says:

    I found this post by Urs Schreiber at the n-category cafe on the difference between local and global supersymmetry to be very enlightening.

  32. KD says:

    Chris:

    Is there empirical evidence that “the running coupling constants meet precisely at the GUT level”?

  33. chris says:

    if they meet they meet at the GUT scale, because that’s how the GUT scale is defined.

  34. rhofmann says:

    Peter,

    I completely agree with you in seeing the phenomenological industry as a necessary consequence of the hyping spear head of “deep” theory. Trying to make a connection to nature of “deep” theoretical concepts certainly was pleasing some of the formalists until it was universally realized how obviously embarrassing this industry became. (The story about black holes at LHC in connection with extra dimensions that developed its own life after being received by broader society, …)

    Keep on pushing, Peter. And thank you again.

  35. Peter Woit says:

    Justin,

    I think that counts Urs as another string theorist now throwing SUSY under the bus. He does make clear that what is at issue here is space-time SUSY, which is what the LHC can test. There’s also world-sheet SUSY , SUSY in the 1+1 d world-sheet of the string, which goes back to the earliest days of SUSY. That’s a different issue. He also makes the good point that there’s SUSY QM, the 0+1 d case, where a form of SUSY show up in the simple theory of a spinning particle. That’s a very important and deep idea, but it’s not 4d space-time SUSY, which is what the LHC is looking for.

  36. Peter Woit says:

    abbyyorker,

    There are always people willing to swallow hype about untestable ideas. I think they are a minority though among professional scientists, even if some of them get a lot of exposure in the media. If they deal with the LHC ruling out their favorite ideas by changing them to make them untestable, they’re not going to have much credibility with their colleagues. Whether the popular media continues to give them prominent attention will be interesting to see.

  37. somebody says:

    Among the physics bloggers, Lubos is probably in the top one or two when it comes to his grasp of the subject matter. No two ways about it. That doesn’t mean that his OPINIONS, even about physics, aren’t crazy sometimes. What I always find amusing is when people -including him- say there is a 90% (or 50% or 0.001% or whatever) chance of finding SUSY. Either we find it or we don’t. Percentage a-priori probablities are emotional nonsense.

    I also don’t understand what it means when people say the LHC is “ruling out” parameter space for SUSY. Do they mean the soft-breaking parameters of the MSSM? If that is the case, I think it is important to keep in mind that weak-scale SUSY is a much more general thing than our sociologicakl obsession with the minimal supersymmetric extension of the standard model. Weak scale SUSY is a nice idea – MSSM is just the simplest realization of it. Even weak scale SUSY could be wrong, but it is not going to be so easy to rule in/out SUSY without some serious time and hard work, it seems to me.

    And finally, as Peter correctly points out, string theory does not make the prediction of weak-scale SUSY. It will be good to find susy somewhere because string theory is ultimately supersymmetric, but there is no reason why it should already be there at minscule energies like the weak scale.

  38. Technicolor says:

    I am also wondering about the technicolor question posted by Yousuf. If the Higgs and SUSY is not found is the only other theory technicolor (which I have heard is a very ugly theory)? What theories get promoted if we find nothing?

  39. manyoso says:

    Technicolor is not the only alternative to Higgs for explaining electroweak symmetry breaking: http://en.wikipedia.org/wiki/Higgsless_model

  40. Dan says:

    Peter, I disagree on technicolor. Recently a lot of composite Higgs models showed how difficult it is to distinguish some of these composite states from a Standard Model elementary Higgs.

  41. Shantanu says:

    so if no supersymmetry is found at LHC accessible energies are all proton decay
    models ruled out or can one have proton decay but no supersymmetry?
    shantanu

  42. multigoal says:

    Peter
    Two questions: 1) What do we mean by SUSY being ruled out?… it’s actually CMSSM that is getting ruled out, right?
    2) What beyond standard model we can learn from LHC if they find 114-150 GeV Higgs and nothing else?

    Multigoal

  43. Neg says:

    PW,
    Would the data the LHC is collecting from now to the year’s end be enough to either find or r/o higgs in the interesting region of 114-140? And SUSY?

    I understand the LHC will power down to save on money. Then restart, again, but it will be another 3-5 years before it reaches design beam collision energy of 14 TEV?

    What additional physics is the higher 7/beam 14 TEV is supposed to find over the original 3.5/7Tev?

    Any word on when SuperCDMS and the Xenon100 dark matter detection ?

  44. Peter Woit says:

    Shantanu,

    Sure, you get proton decay in non-SUSY GUTs. Actually, this is one of the arguments for SUSY: non-SUSY GUTs have lower unification scales, so higher proton decay rates, mostly already ruled out by experiment.

    multigoal,

    You can’t completely rule SUSY out by experiment, since one can always find regions in its huge parameter space that are inaccessible to experiment. You can make it a lot less plausible by showing that the sorts of regions of parameter space intensively studied by theorists as the most likely place for it to be are ruled out. The CMSSM involves a particularly simple choice of parameters, but I don’t know that moving away from that simple choice to a random generic one changes the conclusion (the LHC results would still rule it out). Expect to see lots of frantic back-pedaling by SUSY theorists over the coming days and months, saying that the analyses they published pre-LHC are now to be ignored, instead you should pay attention to their latest effort to find some SUSY models that aren’t ruled out by the LHC.

    The Higgs is the most dubious part of the SM, best bet for falsifying the SM is to either rule it out, or observe it and see that it behaves differently than expected. If the SM Higgs works perfectly, it may be possible there is no observable violation of the SM at LHC energies.

    Neg.

    I suspect this year’s data may be enough to see the Higgs if it is there. If not, the 2012 data should do it. The exclusion of more and more SUSY models should continue as more analyses are done, but I don’t think you’ll see another big jump in energy scale of SUSY exclusions until the machine energy is raised. They’re shutting down the machine in 2013/4 not to save money, but to fix the magnet interconnections. This is a huge job, they’re a lot of them. It is supposed to come back on early 2015, presumably mid-late 2015 will see first higher energy results.

  45. Leonard Lerner says:

    I do not understand whar all this Higgs excitement is about. Most of the excess at 120-130 is driven by the WW channel, while the othetr channels show nothing extraordinaty in this range. Its a differential signal in all channels that would indicate a Higgs, an integral over the channels, where most of the excess comes from one of them is more likely a background error

  46. DGP says:

    While I might agree with “Somebody” that Lubos Motl is still reasonably on the ball as far as physics is concerned (without giving support to his fanaticism about strings and supersymmetry or endorsing his view that worries about the validity of renormalisation schemes are evidence of a weak mind), I observe that the physics postings in his blog now get very few comments compared to the global warming denial and general right-wing politics ones. It wasn’t surprising that he has been accused of being a holocaust denier since he seems to have adopted most of the other baggage of the unsavoury wing of European right-wing politics. It looks like most physicists have given him up.

    Does anyone know how he is funded now? I assumed he had taken an academic appointment in his native Czech Republic but that doesn’t seem to be the case.

    His view of phenomenologists is on a par with his other prejudices. One would hardly gather from his diatribe that HEP experiments could not proceed without good hands-dirty theoreticians to help design the experiments and compute the backgrounds. I have said before that I am awed by the difficulty of the background subtractions in modern experiments.

  47. DB says:

    @Leonard.
    It’s pretty straightforward. It’s just competitive human nature. The Tevatron, about to be shut down, is engaged in the same sort of “I think I see a hint of something there” that LEP2 was up to just before they were shut down (to make way for the LHC). In response, the LHC has uncovered “hints” of their own.
    The competition between American and European accelerator communities has been the very lifeblood of particle physics since the field’s inception and is a very healthy thing. It’s a great pity that the US will have effectively exited experimental particle physics once the Tevatron shuts down. Who’s going to keep those pampered fois gras munching Europeans on their toes now? (I jest, I jest)
    Unfortunately, naive, gullible journalists with little understanding of the field’s history can’t see this for what it is. A harmless outbreak of I-wanna-be-first-itis.

  48. Henry says:

    CMMSM or CMSSM?

  49. Peter Woit says:

    Henry,

    Thanks, fixed. It’s Constrained Minimal Supersymmetric Standard Model.

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