New LHC Results

This week results are being presented by the LHC experiments at the Moriond (twitter here) and Aspen conferences. While these so far have not been getting much publicity from CERN or in the media, they are quite significant, as first results from an analysis of the full dataset from the 2015+2016 run at 13 TeV, This is nearly the design energy (14 TeV) and a significant amount of data (36 inverse fb/experiment). The target for this year’s run (physics to start in June) is another 45 inverse fb and we’ll not start to hear about results from that until a year or so from now. For 14 TeV and significantly larger amounts of data, the wait will be until 2021 or so.

The results on searches for supersymmetry reported this week have all been negative, further pushing up the limits on possible masses of conjectured superparticles. Typical limits on gluino masses are now about 2.0 TeV (see here for the latest), up from about 1.8 TeV last summer (see here). ATLAS results are being posted here, and I believe CMS results will appear here.

This is now enough data near the design energy that some of the bets SUSY enthusiasts made years ago will now have to be paid off, in particular Lubos Motl’s bet with Adam Falkowski, and David Gross’s with Ken Lane (see here). A major question now facing those who have spent decades promoting SUSY extensions of the Standard Model is whether they will accept the verdict of experiment or choose a path of denialism, something that I think will be very damaging for the field. The situation last summer (see here) was not encouraging, maybe we’ll soon see if more conclusive data has any effect.

If the negative news from the LHC is getting you down, for something rather different and maybe more promising, I recommend the coverage of the latest developments in neutrino physics here.

Update: Lubos has paid off his bet with Jester. Losing the bet hasn’t dimmed his enthusiasm for SUSY. No news on whether David Gross has conceded his bet.

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60 Responses to New LHC Results

  1. new says:

    do you ever plan to publish an update to your 2005 book, updated with these latest results?

  2. Shantanu says:

    Peter I am still waiting for your post (promised after 2015 Nobel prize) on why non-0 neutrino mass is important and the impact of non-zero neutrino mass on BSM.
    (From John Ellis talk at PI, he mentioned that we still don’t have a clue about how to connect BSM physics at TeV scale with neutrino mass measurements)

  3. flavor physics says:

    Not only neutrino physics. Also quark flavor physics too!, in particular from the LHCb experiment. There are other things than ATLAS and CMS direct searches 🙂
    Several measurements in flavor physics, none conclusive alone, seems to all point towards a change in C9 Wilson coefficient. On top of that, LNU (Lepton Non Universality) also adds some spice in flavor physics.
    See, eg, Joaquim Matias’ talk @Moriond EW
    https://indico.in2p3.fr/event/13763/other-view?view=standard#2017-03-22

  4. Peter Woit says:

    new,
    No plans for anything like that now, I’d rather spend my time on other things. I just took a look at the chapter on supersymmetry in my book. It was written nearly 15 years ago, but I think stands up very well. It explains the long list of problems with SUSY extensions of the SM, and lists exactly two positive arguments for such models: one is the approximate unification of coupling constants, the other is the prediction of new weak-scale physics, observable at the LHC. That second argument is now gone, and I don’t see any continuing reason for anyone to take these models seriously.

  5. chris says:

    flavor physics,

    for me the interesting thing is not the appearance of flavor “anomalies”, but that LHCb has seen so few of them until now. Throughout the last decades, these anomalies came and went and it speaks for the quality of the LHCb analysis techniques that they produce so few false positives.

    I will take any bet that these “anomalies” will be gone for good before long (i.e. with the next order of magnitude increase in integrated luminosity).

  6. new says:

    In light of LHC not seeing any hints of SUSY, and your book NEW, what are the implications to string/m-theory research and debate, esp the claim that string theory does not require low-energy SUSY, and there are string vacua that are entirely non-susy?

  7. Peter Woit says:

    new,
    I don’t want this to turn into the usual arguments about string theory. That said,
    the problem for string theory is that the standard response from string theorists for many years when asked “how can string theory be tested” was “by finding supersymmetry at the LHC”, see for instance here
    http://www.math.columbia.edu/~woit/wordpress/?p=3864

    Now that hope is gone, there really is no answer at all to this question, and claiming to have a wonderful theory of everything that makes no predictions and can’t be tested is not a comfortable situation to be in.

  8. Hans says:

    Peter,

    There is that famous graph showing that the three coupling constant unify at a certain energy when supersymmetry is taken into account. The same graph also shows that above that energy, the coupling constants diverge again. How is this second fact explained by supersymmetry fans?

  9. Graham says:

    Looks like Lubos is negotiating payment to Adam, possibly involving a pigeon 😉
    https://twitter.com/Resonaances/status/844218605638103040

  10. Peter Woit says:

    Hans,
    What is supposed to happen in a GUT is that there is a new Higgs-like sector that breaks the GUT symmetry to SU(3) x SU(2) x U(1). Above the GUT scale these degrees of freedom contribute and the dynamics changes. The necessity of introducing this new sector and the various problems it causes is one of the main drawbacks of GUTs.

  11. Hi Peter,

    thanks for the link to the NeuTel blog! Indeed I concur that neutrino physics and astrophysics is where the most interesting results are going to appear in the near future…

    Cheers,
    T.

  12. Low Math, Meekly Interacting says:

    Hoping to see a post from Jester soon. His blog’s been dormant for a while, causing me some worry it will be orphaned…

    While the last shovel-full’s of soil are being spread over SUSY’s coffin, it seems worth noting the graveyard has gotten rather full these past few years. Are there ANY ideas left that are both compelling and have some hope of being tested experimentally by 21st century humans and their colliders?

  13. new says:

    Peter could you please clarify this scientific issue,

    do the current null results based on 36fb-1 @13TEV completely falsify the hypothesis of natural SUSY, or is there still a parameter space remaining for natural SUSY, perhaps that a future proposed 100 TEV collider is required to eliminate?

  14. Peter Woit says:

    new,
    The problem is that “natural SUSY” is not a well-defined concept. It’s basically the idea that SUSY explains the weak scale (say 200 GeV), and thus implies that the SUSY-breaking scale should be roughly that. Already at the Tevatron, there were bounds above 200 GeV for gluinos and no evidence for any SUSY particles, so enthusiasts were saying “it’s only “roughly”, so maybe parameters are “tuned” to the extent of only being 10% of what you might expect”. With the LHC results they have to say, “maybe only 1%” of expected, After nothing is found 50 years from now at a 100 TEV collider they’ll say “maybe only .1%”.

    Besides this generic problem, there are 105 or so extra parameters in minimal SUSY models. You can try and evade LHC results by picking these to have special values making sparticles hard for experimentalists to find.

    The fundamental situation though is that SUSY never provided a compelling explanation of anything about the SM, and is much, much more complicated (see my old book for details). So, not seeing anything is exactly what one would expect, and arguing for more and more implausible explanations for why your idea failed as expected is becoming more and more pathetic (and fewer and fewer are willing to go down this route).

  15. Thomas Larsson says:

    Sigh. I’m not sure that I want to say this, since I have found that I agree with Lubos on most things (including some politics), but I feel that I should point out that my ten-years-old theorem still holds.

    Theorem [Larsson 2007]
    Supersymmetry will not be discovered at the LHC.
    Proof: String theory predicts supersymmetry (Witten 1984-2002). String theory predictions are always wrong. Hence supersymmetry does not exist, and will in particular not be found at the LHC. QED.
    Corollary
    Lubos Motl will lose his experimental-susy-by-2006 bet.

  16. Yatima says:

    Science/Popular article in Nautilus about the search for the 5th force spotted:

    http://nautil.us/issue/46/balance/the-fifth-force-of-physics-is-hanging-by-a-thread

  17. pval says:

    “The chance that they are just a random statistical fluctuation is tiny, says Feng: about 1 in 100 billion.”
    http://nautil.us/issue/46/balance/the-fifth-force-of-physics-is-hanging-by-a-thread

    I’m going to assume this is referring to Krasznahorkay et al (2015; https://arxiv.org/abs/1504.01527). There was a lot of this “transposing the conditional” surrounding the LIGO results as well. As a layperson wrt physics I find the continued misinterpretation of p-values in physics discussions disconcerting. If the people interpreting physics data do not understand the tool they are using, how can we trust their conclusions?

    Some explanation can be found at these links:
    http://rationalwiki.org/wiki/Confusion_of_the_inverse
    http://andrewgelman.com/2013/03/12/misunderstanding-the-p-value/

  18. Peter Woit says:

    Yatima/pval,
    The “fifth force” story really is a different topic, and, honestly, one I personally don’t think is worth paying a lot of attention to. It’s yet another example of the general principle that “extraordinary claims require extraordinary evidence”, and the evidence here is definitely not extraordinary.

  19. emile says:

    pval: “If the people interpreting physics data do not understand the tool they are using, how can we trust their conclusions?”

    Experimentalists in big collaborations understand p-values and you will not see a paper with such a mistake published (though students may make similar mistakes). I don’t know if Feng was correctly quoted but theorists do not work on a daily basis with statistics or the interpretation of data. Anyway, I would not decide that “physicists” can’t interpret data based on a quote from a theorist.

  20. hyd says:

    Ideas that do not work do not die out by themselves. They die out only after their creators die. This is what history has shown to us. So, I predict however negative the evidences to come out, those with SUSY will not stop pushing their ‘agenda’ until their last breath. Those people will keep jiggling with their models and playing all ingenuity, acting as if they were the GOD. It may well take/waste another few generations to fully quench the zeal.

  21. Peter Woit says:

    hyd,
    Unfortunately I’m not so sure that the ideas of the supersymmetric standard model, string theory unification, and the multiverse will die out with their creators. These creators are already no longer with us or retirement age and losing influence, but their failed ideas have been rather successfully institutionalized, and several generations of younger physicists have been trained in them. Will they abandon these ideas? Will those promoting them to the public and to young people entering the profession stop doing this? So far, I’m not optimistic…

  22. GoletaBeach says:

    The overwhelming majority of humans alive today believe all sorts of supernatural phenomenon are real. That a tiny minority who believe in rationalism, applicable mathematics, and the scientific method held on throughout millennia of being imprisoned , burned at the stake, etc, had their ideas survive to influence modern thought is actually a remarkable story… and we scientists are still a minority.

    The truth is… whatever the results of well-conceived and executed experiments, like those of the LHC, turn out to be, we all win, because we learn what Nature really is. As Luis Alvarez said about search with muons for chambers in the Egyptian Pyramids: he didn’t fail to find new chambers, is succeeded in proving there were no further chambers to speculate about.

    The human dramas of betting and pilloring famous theorists who made wrong predictions may be interesting and fun, but it is just a social sideshows. SUSY might easily be correct but it might take humans another 10,000 years to discover that. Science itself doesn’t give a darn about human lifetimes.

    The snickering and schadenfraude about LHC not finding SUSY is hardly a blip in that process, but to the extent that creative ideas to empirically probe SUSY and all other conjectures get inhibited by the snickering, that is unfortunate.

    Independent of theorists’ ideas, hadron colliders remain the best tool to probe higher energies in actual experiments (as opposed to observations). LHC did and is doing a tremendous job, but likely we have learned that the SSC was even more important as a pathfinder than we thought in 1994. Mel Schwartz was right… he never cared much about the SUSY theorists. Go to the highest energy you can afford… that is always a compelling discovery strategy. The only role theorists really have is to run a propaganda front among the supernaturalists for what is completely obvious to experimentalists.

    Unfortunately, propaganda is an issue of human drama, and it certainly is true that the propaganda can backfire.

    Personally, given that the LHC was unconditionally a terrific empirical endeavor, I don’t much appreciate criticism of the over-enthusiastic theorists. Their true role was over when the LHC was well funded… they helped do that. After that, science will little note nor long remember what they said, but what the experimentalists did will be never forgotten.

  23. Peter Woit says:

    GoletaBeach,

    It’s not “snickering”. It’s extremely important for theoretical physics that ideas that don’t get work get discarded, a disaster if they don’t, but instead become the dominant paradigm for the field. These SUSY models have always been highly problematic and heavily oversold. Pre-LHC one could argue that the “naturalness” argument justified waiting for the LHC results before abandoning them completely,. The results are now here and these models should be given a decent burial. Getting influential theorists to acknowledge that the models are dead is quite important, and the point at which they pay off their lost bet is a good time for this to happen.

    For experimentalists, the issues are different. Finding the Higgs is a great achievement, but so is exploring a new energy range and finding out what’s there (and what’s not there). Killing off SUSY is an achievement they should be proud of. Going forward obvious goals are to do the best possible job of studying the Higgs sector, as well as to do the best and most complete job of exploring the energy range the LHC can reach. This is up to the experimentalists, but it seems to me that they should be thinking about how best to weight effort aimed at further SUSY searches versus other kinds of analyses. Fine if you like having bad models to use as propaganda, not so great if you believe your own propaganda and it blows back on you and damages your work.

    If there is some way to afford it, I agree that a higher energy machine is desirable. I don’t think though that bogus arguments about how such a machine is likely to find SUSY or produce black holes are going to be effective. It’s not the ignorant masses that will decide whether to spend the money, but people who are a lot more sophisticated, and trying to pull the wool over their eyes with a dubious argument I think will be counterproductive.

  24. Gregor says:

    Peter,

    why is a higher energy accelerator desirable? We have experiments that show clearly that the standard model is correct; we have calculations/theory showing that it is correct up to (almost) the Planck scale. We have no difference between theory and experiment. None.

    The only thing we lack is a theory showing that the standard model is consistent with general relativity and at the same time predicts the 20 parameters of particle physics. This is a much simpler exploration, much less demanding, and well in reach in a few years time. A friend of mine would gladly take bets with real money that this scenario is correct.

    With all data available, pouring money in a new machine seems an almost certain waste. A quick overview of the arguments in favor of such a machine shows that all these arguments (supersymmetry and its particles, wimps and other microscopic dark matter, more dimensions, superstrings, microscopic black holes, axions, additional generations, more Higgs bosons, fifth force, and dozens of others) have already been put aside by the LHC. Why should we look in a corner of nature when we already know quite definitely that there is nothing to be found there?

    Other arguments for a machine (strong CP problem, dark matter, etc.) are based on astrophysical data, which is shaky anyway.

    This “why?” question is a serious one. The hope that there is something at higher energy that can be found is based on wishful thinking, not at all on experimental data.

  25. Anonyrat says:

    We need high precision tests of every term in the Standard Model.

  26. Marc Nardmann says:

    Gregor,
    you wrote: “we have calculations/theory showing that [the standard model] is correct up to (almost) the Planck scale.” I would like to understand this claim: “correct” in which sense, given the lack of experimental data between the LHC and Planck scales; what kind of calculations (perturbative? at which order?); what precisely are the results. Could you give a few references?

  27. Pingback: Supersymmetry: String theorists losing bets? Resorting to “denialism”? | Uncommon Descent

  28. Peter Woit says:

    Marc Nardmann,

    I assume Gregor meant “consistent”, not “correct”

    Gregor,

    I think the argument “because it’s there” is a perfectly good one for doing experiments to probe a higher energy scale. Yes, we have no good theoretical reason for expecting something new, but theorists are often wrong about such extrapolations.

    Maybe the LHC will yet find something unexpected and that will give a target for what to investigate. If not, investigating the Higgs sector would be a major goal, especially measuring self-interactions of the Higgs.

    The problem is not that there’s no good physics to be done at higher energies, the problem is the cost. If it were $100 million, Jim Simons could finance it out of the spare change in his couch and it would be obviously worth doing. At $1 billion, it could be financed within the current budgetary envelope of CERN and also I think would obviously be worth it. The problem is that to get to a much higher energy scale, a larger ring is needed and that is going to be very expensive, $10 billion and up.

    For order of magnitude $1 billion, you might be able to build the HE-LHC (same tunnel as the LHC, higher field strength magnets, doubling the energy). Again, the question is money, is that size jump in energy worth the cost?

  29. Gregor says:

    Peter,

    I understand what you say; but we should first give 10 theorists 1 million each with the aim to find a consistent theory showing that general relativity plus the standard model is all there is (including my friend). And we should give 10 theorists 1 million each to come up with a correct theory that predicts something at higher energy.

    Only if they first group finds *no* such theory, and the second group finds at least one, should we really spend 10 billion on an accelerator; at the moment the risk of not finding anything new is much too big.

    After all, the LHC has “only” found the Higgs, not much else. And it confirmed the standard model. One could indeed argue (which I do not) that the last 5 years of operation of the LHC were not worth the money spent. So we will all have a tough time arguing for a new machine. Especially so if theoretical desert scenarios and new theoretical options have not been explored fully beforehand.

  30. GoletaBeach says:

    I suppose prior to about 1492, Europeans questioned the utility of sailing west. Peter is absolutely right: sailing west because you can is and was sufficient reason to do so. There will always be theorists who say this and that… when you have a new technology (like navigation and sailing ships in the 1400’s) and can do something truly new and different (like sail long distances on the world’s oceans) a fine strategy is to do everything you can to get self-appointed smart people to support you. And forget their reasons for doing so… new sources of gold were the argument in the 1400’s, but in reality, the potato and a new land for Europe’s malcontents were the big payoffs.

    Pretty much all hadron collider experiments use the same tools whether one looks for SUSY or not… 1)look for unexpectedly large observable cross sections for every final state you can think of… (Rutherford invented this technique in 1910 or so) 2)look for missing energy (Ellis & Wooster invented this one in 1928 or so). Those are the classics. SUSY is just another excuse to re-do the classics at higher energy.

    It is extremely simple radiation physics (synchrotron radiation) that leads us to hadron colliders rather than lepton colliders, although Peter is right again… precision Higgs studies at a tuned electron positron collider are an excellent idea right now. Because we can, and the analogous history of finding new physics based on small effects (charm quark mass from K0-K0bar mixing, top quark from K0-K0bar CP violation, Higgs mass from LEP precision electroweak) has been successful.

    Something or another is keeping the Higgs mass so small. Something or another regulates quantum field theory at high energies. The Energy Frontier remains a good way to seek solutions to that puzzle. But as Peter says, we can’t because it is just too darned expensive at the moment. Lots of people have been saying “do accelerator research” for 30+ years. The fact is people do that but maybe improvements are no easier than reductions in the cost of using neutron flux to turn lead into gold.

    I’m confident in 10,000 years human kind will find a way, though. Or maybe 50,000 years. Maybe not in my lifetime or the lifetime of any blog poster here.

    But at the same time… more human lives will be saved more cost-effectively right now by purchasing air-conditioners for senior citizens suffering through hot summers in St. Louis, then by spending on high energy physics. The same was true in 1400’s Europe… every dollar given to Columbus would have saved more lives, in the short run, had it been spent on food for the poor. It is an eternal paradox.

    Like the paradox that the very best batting average in a season of American pro baseball was 0.440. Not even 1/2 the time did Hugh Duffy get a hit! Research has a lower batting average. If anybody wants certainty in research endeavor, they really don’t want to do research at all.

  31. martibal says:

    “I assume Gregor meant “consistent”, not “correct””

    And what about the instability of the Higgs vacuum ? (the fact the the quartic coupling of the Higgs become negative at high energy). Is that so much consistent ? Strictly speaking it is not a contradiction, but it is very weird, no ?

  32. Anon says:

    The major challenge is in writing the Lagrangian that includes neutrino masses/couplings. There is no standard way of writing the SM Lagrangian for neutrino masses/couplings. So whether it is BSM or SM, what is the Lagrangian? How can we test it? Those are the questions.

  33. Peter Woit says:

    Gregor,
    I think we can accurately predict the results of giving $1 million to 10 theorists…

  34. B'Rat says:

    GoletaBeach,
    I find the Columbus analogy rather bizarre. One should remember that his aim was not “let’s see if there’s a new continent to plunder”, but “my calculations show that Asia is within reach by our ships”. Too bad his contemporaries actually knew that his calculations about Earth’s circumference were wrong, and that thus had America not existed Columbus and his sailors would have died a rather sad death in the middle of the Ocean. This explains why he found so difficult to fund his voyage. In essence, he was a lucky idiot.

  35. emile says:

    Anon: what about giving the neutrinos dirac masses with small yukawas?

  36. Ellsberg says:

    An interesting take on events these days: http://vixra.org/pdf/1703.0300v1.pdf

  37. GoletaBeach says:

    Or maybe Columbus was just utilizing advances in shipbuilding and navigation to try to do something really interesting. Of course the Talavera commission knew his crew would die of scurvy prior to reaching Japan. What they knew was… completely wrong.

    Of course Columbus was a lucky idiot. And pretty much every great, truly (as opposed to bureaucratically) transformative discovery is lucky idiocy too.

    There on the Berkeley campus in the early 1930’s was Lawrence and his crew slaving away making medical isotopes to pay for the little bit of research they could do between midnight and 6am. When news came from Cambridge of the neutron’s discovery, they realized that the neutron flux from their cyclotron exceeded that in the European setups by orders of magnitude, and they had in fact neutron activated their entire lab, but had failed to notice because they didn’t hunt for radiation when the beam was off.

    Perhaps they were unlucky idiots… a little more creative exploration without a good reason and they could have been lucky idiots, and discovered the neutron, which is the biggest game-changer in nuclear physics.

  38. Unmanned says:

    I look forward to unparticles being quickly detected and analyzed in Mr. Un’s uncollider.

  39. Anon says:

    emite — sure you can add right handed neutrinos to the standard model and give the neutrinos small dirac masses by choosing their yukawa couplings to be very small ~10^-12.

    So how do you test this?

    You need to measure the Higgs Yukawa coupling to the neutrino or you can disprove the idea by showing that the neutrino is a Majorana particle and not a Dirac particle.

    Alternatively, you can say that you will add 3 right handed neutrinos and include a Majorans mass terms and do the seesaw mechanism in the std model. Again you can test this by trying to find the right-handed neutrinos Majorana mass scale. But this scale may not be reachable by colliders.

    Or you can say you wont add 3 right handed neutrinos but add a Higgs triplet to SM and give the left handed neutrinos small Majorana masses directly (Called Type 2 seesaw). You can test this by finding the Higgs triplet — but it could be at some very high seesaw scale that is never reachable by colliders.

    Essentially the neutrino sector of SM is as untested as the neutrino sector of BSM.

    In fact in BSM you may be able to think of more consequences (non-collider as well) and test for those consequences. SO BSM can be more testable than SM. For example proton decay for GUT theory, vanishing of leptonic CP phase for minimal left right symmetric model with parity (as leptonic \delta_CP contributes to strong CP phase in one loop in LR symm model).

  40. Anon says:

    sorry emile mis-spelt your name in the above response.

  41. Gregor says:

    Peter,

    you are right to make fun of theorists. The LHC was sold/marketet to politicians as the machine to search for the Higgs, for supersymmetry, for dark matter and for hidden dimensions.

    How would you sell the next collider, especially in the light of the last results? (1) We cannot use the same arguments any more. (2) And you need a good theory to provide arguments.

    Susy and strings were wrong, but provided 3 of the 4 arguments for the LHC. On the other hand, showing that the standard model is correct and consistent is not an argument for a new machine. If the theorists cannot provide a good vision for the future, there will be no new machine.

    Wasting 20 millions on 20 (or more) theoretician’s salaries is much less than wasting 10 billions in a machine with the risk of getting no results. But of course your making fun of the idea is also valid! After all, we just have to look at hep-th to see that nothing is coming from that side since quite a long time. So shall we stop here?

    Peter, let me ask you directly: (1) If you had 10.02 billions at your disposal for the coming 10 years, how would you spend the money? (2) What arguments would you provide?

  42. Peter Woit says:

    Gregor,
    The problems of theoretical physics I don’t think are ones that can be addressed by simply putting more money into the field. They’re a different story. Redirecting money from experiment to theory will solve nothing.

    Doing things like telling the public that the LHC was designed to find extra dimensions was even at the time clearly a really bad idea. It wasn’t necessary to get the LHC funded, and engaging in outrageous hype like that creates a serious credibility problem next time you have a new project that needs funding. So, going forward, that will be a big problem, and doubling down with “the extra dimensions are at 10 TeV rather than the 1 TeV we thought” is unlikely to work.

    The problem isn’t the coming 10 years, I think experimentalists have made reasonable choices about plans for the next 10 years, with $1 billion/year the order of magnitude that is planned. At the energy frontier, it will be the HL-LHC.

    The problem is the longer term. Absent some new information, I don’t think HEP can successfully argue that there is a good reason to redirect resources from elsewhere and put significantly more money into the field. Maybe it can hold onto its current funding level and then there’s a difficult problem of how to allocate that. How much should go to a new energy frontier machine and of what kind? People are very actively looking at the possibilities, and at some point will have to focus on the price tags and how to proceed.

  43. B’Rat,

    The luck of Columbus was that he came back. Just think if he hadn’t — as, in hindsight, was much the likelier outcome.

  44. Darrell Burgan says:

    I don’t suppose Motl actually admitted he was mistaken … ?

  45. Cobi says:

    Darrell,
    the bet was 100 to 1, i.e. Motl would have won 10,000$ if SUSY were found given the current set of data. No matter how you think about Motl, there is nothing to admit after a bet of this type. In the end they made assumptions about Bayesian probabilities.

  46. Peter Woit says:

    Cobi,
    Jester’s bet I think was significant mainly in that it made clear that there were many theorists (Falkowski is a rather mainstream theorist) who not only thought that the LHC would not see SUSY, but that SUSY was already, pre-LHC, an idea that hadn’t worked, so it was not only unlikely the LHC would see it, but very unlikely.

    As for Lubos, when the LHC turned on, his description of the probability of seeing SUSY was that “many of us ” thought it was “90% or higher”, but would publicly say “60%” just to be “modest”, see links here
    http://www.math.columbia.edu/~woit/wordpress/?p=3864
    He later revised that down to “50%”.

    I’ll leave it to the Bayesians to explain the significance of a scientist claiming his theory predicts something specific with “90% or higher” certainty, then claims it doesn’t matter, his theory is still a sure thing, when the specific prediction is falsified.

    What is much more significant than what Lubos has to say is what the most influenced and respected theorists pushing SUSY now will have to say. I have in mind in particular Gross, Wilczek and Witten (although Witten as far as I know never bet anything on this).

  47. GoletaBeach says:

    Oops Peter… the proposers and sellers of the LHC never said the “LHC was designed to find extra dimensions”.

    https://press.cern/press-releases/1993/12/large-hadron-collider-presented-cern-council

    Maybe some theorists who were uninvolved in the real spadework to achieve approval of the LHC came in later and cut in to the front of the parade… wouldn’t be the first time.

    Actually, in 1993, the SSC was sold on “no-lose” for Higgs observation. If they Higgs was not observed, you’d see strong W-W- scattering at the SSC. No lose. No mention of extra dimensions, many worlds, etc.

    Then gradually precision electroweak measurements from LEP, SLC, and CDF indicated that the Higgs would be light and Atlas & CMS decided to shell out for >$100 million calorimeters to see Higgs to gamma gamma. They were right! And at the time not a few committee reviewers wailed on them, but they held fast to the need for highly segmented, fast calorimeters.

    Funny how that really great story sometimes gets buried under some speculative smoke by opportunistic theorists.

  48. Peter Woit says:

    GoletaBeach,
    I understand, the extra dimensions was theorist hype that appeared later, around 2000. For an example, see the classic New York Times article “Physicists Finally Find a Way to Test Superstring Theory”
    http://www.nytimes.com/2000/04/04/science/physicists-finally-find-a-way-to-test-superstring-theory.html

  49. GoletaBeach says:

    Well, thanks Peter. Sure… not an experimentalist, nor an LHC advocate like Rubbia or Llewellyn-Smith even interviewed in that NYT article… and most certainly none of the machine builders themselves, or the detector leaders like Jenni or della Negra.

    You have made me wonder if the “real story” of the LHC… how the US was against it due to the SSC and the SSC “No-Lose” theorem, thought to need 40 TeV in the center of mass, to see the Higgs, was proven to be irrelevant first by loop effects evaluated at the LEP/SLC/CDF energies, and then by observation of the light Higgs itself… will ever be told.

  50. tulpoeid says:

    “Lubos has paid off his bet with Jester.”

    At least with this piece of news we know that Jester is healthy and doing well. But no motivation to post even on Moriond and on April fools’? HEP not doing much the same.

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