Friday, 12 September 2008

What will the LHC discover

The excitement generated by the LHC kick-off last week is still in the air. I'm beginning to realize that soon we will k.n.o.w. Which means that it's the last moment for gambling and wild guessing. Here are my expectations. The probabilities were computed using all currently available data and elaborated Bayesian statistics.

Higgs boson. Probability 80%
Peter Higgs' kid is ugly and problematic, however his big advantage is that he does his job right. Firstly, he knows how to break electroweak symmetry in such a way that the scattering amplitudes of W and Z bosons remain unitary at high energies. Secondly, if he is not much heavier than 100 GeV, he is consistent with stringent precision tests performed by LEP and Tevatron. No one else can achieve both without complicated gymnastics. That's why Higgs is the safest bet.

Non-SM Higgs boson. Probability 50%
The Standard Model uniquely predicts the couplings of the Higgs to all fermions and gauge bosons. From experience, these couplings are very sensitive to new physics in any form.That's why a precise measurement of the Higgs production cross section and all possible decay rates may be far more exciting than the discovery itself.

New Beyond SM Particles. Probability 50%
That's what particle physics is about, isn't it ;-) Almost any extension of the Standard Model that explains electroweak symmetry breaking predicts some particles in the TeV range. So it seems a good bet that we will see some of the junk. The question is if we will be able to make sense of the pattern that will reveal...

Strong Interactions. Probability 20%
Nature has repeated this scenario all over again: interactions between fundamental constituents become strong and new collective degrees of freedom emerge. Condensed matter physicists see it everyday in their laboratories. In particle physics, the theory of quarks and gluons knowns as QCD at low energies undergoes a transition to a confining phase where it is more adequately described by mesons and baryons. It is conceivable that some of the Standard Model particles also emerge in this manner from a TeV scale strongly interacting dynamics. The problem is that we should have already seen the hints of the composite structure in low-energy precision tests, flavor physics and so on, but we see none of that. The reason why the probability for this scenario remains relatively high is our shameful ignorance of strongly interacting dynamics -- we might have easily missed something.

Dark matter. Probability 5%
All hopes lie in numerology: a stable particle with a weak-scale mass and a typical weak annihilation cross-section of order 1 picobarn would have roughly the right thermal abundance to explain the observed dark matter abundance. If this is the right track, the LHC would grab the most important discovery in the history of collider physics. But we know dozens of other plausible scenarios where the dark matter particle is either too heavy or too weakly interacting to be discovered at the LHC.

Little Higgs and friends. Probability 1%
It is a plausible possibility that the Higgs boson is a pseudo-Goldstone boson whose mass is protected from radiative corrections by approximate global symmetries, a sort of mechanism we see at work in the pion sector of QCD. Proof-of-principle models have been constructed: Little Higgs and Gauge-Higgs unification scenarios. But they are all kind of elephants on elephants...

Supersymmetry. Probability 0.1%
Supersymmetry is just behind the corner. After the LHC she will just pick another corner to hide behind. Supersymmetry will of course be seen at the LHC, just like she was seen in all previous hadron colliders. But, once the data are well understood, she will take a leave and come back into hiding where she clearly feels more comfortable. Susy aficionados should not however be worried. The field will flourish as a new, vast and exciting parameter space above 3 TeV will open for exploration. The wealth of new experimental constraints from the LHC, satellite missions, and dark matter detection experiments will make the-allowed-parameter-space plots colorful and sexy.

Dragons.
Probability $e^{-S_{dragon}}$
This possibility was recently pointed out by Nima Arkani-Hamed. The laws of quantum mechanics allow anything to happen, albeit the probability may be exponentially suppressed for complicated (large entropy) objects. CERN officials maintain there is no imminent danger since the putative LHC dragons will be microscopic (small dragons have the smallest entropy, hence the largest probability to appear in particle collisions) and anyway they will quickly suffocate in the vacuum of the beam pipe. Some researchers, however, have expressed concerns that the dragons might survive, grow, burn ATLAS, kidnap ALICE and lock her in a tower. A more comprehensive study of the potential risks is underway.

Black Holes. Probability $0.1*e^{-S_{dragon}}$
Although microscopic black holes have smaller entropy than typical dragons, the advantage of the latter is that they are consistent with the established laws of physics, whereas TeV-scale black holes are not. There are many indirect arguments against TeV scale gravity, from precision tests, through flavor physics, to cosmology. Certainly, dragons are a bit safer bet.

49 comments:

Anonymous said...

I really hope susy is not discovered at the LHC. It's rammed down our throats with practically every arxiv paper. If they find a superpartner, I may quit physics.

JTankers said...

Dr. Hawking estimated a 1% chance that micro black holes would be created in the Large Hadron Collider and bet $100 that the Higgs would not be found.

Another paper proposing that micro black holes created by the Large Hadron Collider might be stable was published in August.

What is your opinion of Dr. Hawking's predictions?

Anonymous said...

Why spending so much money to discover what you already can buy in stores?
-W

Joseph Conlon said...

I bet you one euro that susy will be discovered at the LHC. If it is not discovered, I pay you one euro. If it is, you pay me five hundred euro (see, I am even generous with my odds!). Deal?

Jester said...

Hey Joe, come on, no risk no fun. Would you bet a considerable sum, say 100 euros, against smaller odds? I heard you guys estimate the chances to be more than 50% :-)

Jtankers, concerning the black holes i don't think Stephen Hawking knows what he's talking about. Concerning the Higgs, people express various opinions, but as i said, so far nobody has been able to present a plausible alternative.

Lumo said...

Wow, supersymmetry has 0.1% here. The fair bet would be 1,000 vs 1. I offer you a magnificent, much better for you 200 vs 1 bet!

My offer is that is SUSY is not found, you will have USD 100. If it is found, you pay may USD 20,000. Think about it.

Jester said...

Ciao Lubos, let's round up to 100 against 10000. In my estimate, 1% is a typical fine-tuning of susy models, and the additional factor of .1 is because it makes me puke (but it would not be wise to place bets based on my gastric functions). Define "supersymmetry found" and we'll have a deal.

drisguntled gozitano said...

well done jester, I love that 0.1% susy. won't bet though, I never liked the argumentum ad crumenam. plus, my personal (and, alas, mainly aesthetic) bias is toward the not-so-favoured new strong dynamics...

Anonymous said...

JTankers said...

"Another paper proposing that micro black holes created by the Large Hadron Collider might be stable was published in August."

Actually no, the Plaga paper argued that some microscopic black holes evaporate *even faster* than conventional estimates of Hawking radiation suggest.
Seriously, if you want to spread fear and disinformation on the web, you should at least take the time to *read* the papers that you're going to use, so that you're not using them to argue exactly the opposite of what they say!

In any case, another paper by Giddings and Mangano appeared almost immediately afterwards, pointing out a trivial but devastating mistake in the Plaga paper.

For an informative analysis of the credibility of Rossler and Plaga see:

http://onscreen-scientist.com/?p=34

Lumo said...

Dear Jester,

your 100 vs 10,000 still sounds very promising, especially because I find your quantitative manipulation with "fine-tuning punishment" misguided and my estimate for SUSY is not 0.1% but around 60%. ;-)

By "supersymmetry found", we could mean that e.g. after 30 inverse femtobarns of data, there will exist at least one paper by ATLAS, CMS, or some combination of them that will claim, in the title or abstract, that they found evidence for supersymmetry and/or superpartners, or that they will have a careful interpretation that "it might be SUSY/superpartner" and there will exist at least one phenomenology paper with at least 10 citations that will claim that SUSY found is the most likely interpretation of the data.

Still sounds OK?

Best wishes
Lubos

Lumo said...

Incidentally, I find your estimate of the odds for black holes also exaggerated.

If you think that it's on par with dragons (or even worse!?), I offer you USD 10 vs USD 10,000 for micro black holes and/or TeV quantum gravity (including RS; because I think that their likelihood is comparable to 0.1% or 1%).

With your dragon estimates, that's another USD 10 for free for you! ;-)

Cheers
Lubos

Ervin said...

"That's why Higgs is the safest bet."

Please note that there are Higgs free models based on nonlinear dynamics of gauge theory that are currently ignored by the scientific community.
See for example:

doi: 10.1209/0295-5075/82/11001

http://www.j-npcs.org/online/vol2005/v8no4/v8no4p366.pdf

http://www.worldacademicunion.com/journal/1749-3889-3897IJNS/IJNSVol3No3Paper02.pdf

http://direct.bl.uk/bld/PlaceOrder.do?UIN=229708841&ETOC=RN&from=searchengine

Jester said...

Lubos, I take the bet with one caveat. Since I'm pretty convinced that there will be false claims of discovering supersymmetry, I will wait one year after the putative CMS/ATLAS paper before I admit defeat.

About RS, I consider it a holographic version of the "strong interactions" possibility, and in this sense there could be strong gravity effects due the graviton mixing with spin-2 excitations from the strong sector. Apart from that, I'm sure there won't be any black holes and similar fireworks. But anyway, one bet is enough, I'm not a damn hedging fund.

Jester said...

Dear JTankers, your comment is deleted because I'm not interested in your brooding. Internet is vast enough, and you can find a different place to make an idiot of yourself.

Claire said...

Thanks for the comment on dragons (vs black holes)... made my day ;)

Claire said...

Oh, and jtankers... About Hawking's prediction, I have a feeling it was more of a consolation-prize bet. In that: if the Higgs is discovered, we have the Higgs. If not, he get's $100. It's a Win either way for him :)

JTankers said...

Did you delete my comment clarifying which paper I was talking about to try to make me look like an idiot?

Good day.

a quantum diaries survivor said...

Jester, I advise you to change the stipulation. Evidence means basically nothing. Tons of distributions will be checked, and if one is above 3-sigma, and it stays there for a while, you'll have your evidence paper.

I advise an observation paper, which is something experimentalists are much more wary of putting out.

Please remember that there are effects which stay there for years before being cured by more data AND a more thorough analysis...

Cheers,
T.

joseph conlon said...

Hi `Jester', you may not want a career as a bookie but if still interested I would take an either/or 100 euros bet between `some kind of susy' and `some kind of RS warped extra dimensions' in favour of susy, with the bet void if neither is seen.

Cheers
Joe

Anonymous said...

And I bet you 10 units of whatever currency you choose that Lubos is not going to pay you a dime no matter what.

Lumo said...

Hi Jester,

very good. Let's forget about the black holes now. Independently of bets, I think that you underestimate how close a path it is from anything about RS to micro black holes.

OK, 1 year sounds fine. If the paper is not generally dismissed after that time, I am the winner.

On the other hand, you're the winner after 30 inverse femtobarns (at 14 TeV, or more than 12 TeV) if no "discovery paper" of this kind is in the waiting line. OK? If there is a paper waiting at that moment, we wait for 1 year to decide.

If we agree about that, it would be helpful to know both e-mail and postal addresses of each other. ;-)

I appreciate your consistency concerning your SUSY skepticism.

All the best
Lubos

as said...

Many theorists spent their lives working on supersymmetry, so betting some money does not add much.

Rather, I would like to bet one Euro for a Dirac fermion with mass 1.5+-0.2 TeV coupled to spontaneously broken gauged muon minus tau lepton number, to be seen at >5sigma confidence level at LHC or elsewhere within 29/9/2011.

What are the quotes?

almidda said...

Jester, take my advice and don't make a bet with the devil. Great post anyway.

Jester said...

Tommaso, I just (naively;-) believe that you guys in Atlas/CMS understand that claiming "the evidence for supersymmetry" takes more than seeing some excess in some channel. Supersymmetry as we know it typically implies a light Higgs, gluino production and cascade decays, missing ET all over the place, and so on (not always all of that of course, but you expect a huge menagerie of signals). Anyway, i'll take your concerns into account.

Joe, I don't really expect warped extra dimensions either. In other words, if strong dynamics appears at the LHC it is unlikely to be large N. I could take a more general bet "some kind of strong interactions" against "some kind of supersymmetry". Though i should really stop gambling now :-)

Jester said...

Lubos, after the night, the general conditions still look fine but we should still agree to some details. For example, about the theory interpretation: there will surely be 100 phenomenological papers with 100 citations each interpreting the data in terms of SUSY, technicolor, extra dimensions, or little green men, so that condition is not really satisfactory. But we can fix these details by email. I'll contact you soon.

Anonymous said...

Just remember the standard investment/speculation/gambling advice, both of you: never risk money which you can not afford to lose.

Nik said...

As: I take your bet; 1 Euro against my usual bottle of "Great Wall" red, so it is both a gamble on physics and the advances in Chinese wine-making in the next few years.

Anonymous said...

cool! i fully agree with your predictions.

Lumo said...

Excellent, Jester. I doubt there will be papers with dragon (or technicolor) interpretations and 100 citations ;-) but fine. I hope you know my e-mail, first name dot last name at gmail dot com.

Best
Lubos

De Bunker said...

Jester, you've managed to invert the normal odds of betting. Normally everyone bets $1, the odds are 99% for supersymmetry, and in the event of its discovery, 99% of the people win $1.01 and the one that bets against it gets nothing. If supersymmetry is not discovered, the guy betting against the crowd wins $100.

You've accepted a bet, betting against the crowd, in which you can lose substantially, but the upside isn't large enough to make betting worthwhile in the first place. So basically you are willing to give up a bunch of money, but this can't be considered a "bet" according to any betting system I've ever heard of.

I had someone offer me a bet of exactly this type before, (because I similarly would bet strongly against SUSY) but I declined for the reasons above. I don't know what kind of collective brain tumor we all have that makes us come up with hare-brained betting schemes. I have to make sure not to go to casinos with any physicists...

I would love to see "real" bets on this topic...there are several "Prediction Markets". Both intrade.com and ideosphere.com have relevant bets including higgs boson discovery (also one at predictify.com, and the cosmological constant. So come on everyone! Put your money where your mouth is!

Jester said...

deBob, you correctly noticed that winning money is not the point here, at least from my point of view. In fact, I always lose in casinos, regardless what the odds are, so I'm not planning to make my living from gambling ;-). The point is to demonstrate that SUSY at the LHC is very unlikely, contrary to what the crowd says.

De Bunker said...

I decided to blog on this too.

And I created a Prediction Market for SUSY. So go bet!

Let's see what the crowd actually thinks...

as said...

dear nik,

the particle we betted on already meets the conditions of the bet. Indeed, as discussed on http://arxiv.org/abs/0809.2409, it explains Dark Matter thermally, it explains the 9 sigma preliminary PAMELA anomaly; it explains the 5 sigma ATIC/PPB-BETS anomaly; and it also explains the 3 sigma g-2 anomaly.

Unfortunately, as I do not drink wine, I would have preferred to win 1 million Euro.

Zuzy said...

Jester, darling, why don't you believe I'll show up soon? Why don't you believe I'm the sexiest girl in town? Boy, you made me cry with your lack of good taste!

But hey, I see you're gonna pay dearly for that with that awful bet!

Anonymous said...

"The point is to demonstrate that SUSY at the LHC is very unlikely, contrary to what the crowd says."

I'm not sure how you did that. You quoted a ridiculously low chance of finding SUSY. Lubos gave you an insanely good bet, if your estimation was accurate, you negotiated and got an even better price for yourself and Lubos still accepted the bet instantly. It seems more likely that you are way, way off here.

Lumo said...

Dear De Bunker,

I think that Jester is very fair about quantification of his (and your) strong language about SUSY.

If someone feels to vomit about people's work involving SUSY, it must really mean that he thinks that the chances don't exceed 0.1% in which case a bet assuming 1% must be a great deal for him.

The people who work on SUSY don't claim that the probability that SUSY is there at the LHC is 99.9% or more. Their estimates are typically close to 50%. Even if it were 10% or 20%, it would surely justify the work on the theory because if the theory is correct, it will be one of the most important developments in particle physics in 50 years.

We're still - privately - discussing some technicalities about the agreement with Jester. He wrote a lot of constructive things. Right now, I am trying to find out why he thinks that the discovery of the Higgs will help to distinguish SUSY from UED because he wants to include the discovery of the Higgs into "my prediction" which is not quite clear to me.

But I guess that all these technicalities will be pretty much irrelevant as long as both of us will insist that the bet is really about SUSY at the LHC and not about some technicalities because this question is likely to be settled and we will probably agree about the answer at the end.

Best wishes
Lubos

Tim Tait said...

Just a technical note on the physics beyond the 'To SUSY or not to SUSY' bet-

You should distinguish whether the bet is for the Minimal Supersymmetric Standard Model, or just a theory which is supersymmetric at high energies. The MSSM has a lot of features such as a light Higgs, two Higgs doublets, and purely Majorana gaugino masses that could be untrue in a SUSY theory with some extra ingredients beyond the SM.

Regards,
Tim

Lumo said...

Dear Tim,

yes, there are many intermediate possibilities but I am personally ready to bet that all the features you mentioned are true, too. The Higgs is light and there must be two doublets. Gauginos only have Majorana masses. I just don't want to depend on the fast speed of the Higgs discoveries because they could be slow.

In the current form of our bet, the intermediate possibilities might leave SUSY "ambiguous" and Jester could win or, if he felt uncomfortably, we would probably agree on a tie.

The bet is not only about SUSY at any energies - because near the Planck scale, SUSY is almost certainly there and a sane person would probably not make a bet against it. It is about the SUSY signatures at the LHC that are strong enough to declare SUSY established by the experiments.

Best
Lubos

Chris Austin said...

Hi Jester,

If it's not too late, may I suggest that you reduce your chance of losing 10,000 USD, by modifying the terms of your bet with Lubos as follows: you lose if the LHC discovers supersymmetry in the four-dimensional sense.

In other words, if the LHC simultaneously discovers both supersymmetry and large extra dimensions, but the supersymmetry is completely broken by the compactification to four dimensions, as for example in my paper linked above, then either you win, or your bet with Lubos is null and void. I think that would be fair, since from one of his comments above, Lubos also does not seem to expect the LHC to discover large extra dimensions.

In compensation for changing the terms of your bet with Lubos, I offer to bet you 100 euros, 1 to 1, that is my 100 euros to your 100 euros, that by Tuesday 12 September 2017, it will be generally accepted, as determined by an independent judge of your choice, that the LHC has discovered TeV-scale gravity and supersymmetry and seven large extra dimensions, and the supersymmetry is completely broken by the compactification to four dimensions.

And if Lubos will agree to change the terms of his bet with you as I suggested, then I also offer to Lubos the same bet that I offered to you.

If you wish I will send my 100 euros stake immediately to be held by a third party who you nominate.

Best regards,
Chris

Lumo said...

Dear Chris,

because both myself and Jester find the LHC discovery of extra dimensions unlikely, your modification wouldn't make much difference according to two of us. However, it is more logical that a discovery of SUSY combined with extra dimensions would mean my victory because it is still SUSY, and it is a stringy kind of new physics that Jester seems to be generally skeptical about.

I would always happily make a 1:1 bet against the discovery of extra dimensions at the LHC: the only thing I dislike is that the "judgment day" is too far.

Your 306-page paper looks much more serious than similar 0-citation papers I have seen in my life: congratulations. (I am even tempted to read a few pages or more.)

Best wishes
Lubos

Jester said...

Chris, i would be tempted to bet against susy + extra dimension: it is like betting against winning the lottery twice in a row :-) But on my side one bet is just enough to demonstrate the point.

De Bunker said...

I find it curious that you make no prediction about extra dimensions. But, since it came up in the comments, I made a prediction market for it too.

Will the LHC discover that there are more than 4 spacetime dimensions?

Place your bets!

Someone suggested a cosmological constant bet. But I'm not sure what quantitative statement can be made that would be worth betting on...

Lumo said...

Dear De Bunker,

I am not interested in da bunk of your bets because they are not supported by anything. If you're not gonna put your own USD 10,000 on the table, you are just another obnoxious and worthless kibitzer of the Woit type who has nothing to say and who carries no responsibility for the lies he emits.

Jester or myself are ready to bet some money which shows that we are not just verbally manipulating but we are serious.

I am making no LHC predictions for extra dimensions because I think that the size of the extra dimensions in string theory is comparable to the GUT scale, 10^{-31} meters or so. They can be larger but I find it unlikely for pretty much the same reasons that lead me to believe SUSY.

Incidentally, if you want to know, you haven't written anything so far that would lead me to believe you that you are a CERN physicist. Compare your rants with Jester or Dorigo or someone else and maybe you will understand what I mean.

Best
Lubos

De Bunker said...

Wow Lubos, that's a lot of vitriol for someone you don't know anything about.

Why should I give a rats ass what you think anyway? You failed to obtain a job in physics, and it's been more than two years since you published a paper. Perhaps you're doing something wrong. Your brand of idiocy seems to bring readers to your blog though, maybe you did find your true calling. Clearly you take your cues from Rush Limbaugh. I hear he makes money. But he's not a physicist either.

It's nice you believe in your opinions at the $100 level. But opinions are like assholes. Everyone's got one, and they all stink. Jester put up the $10,000, not you. You need to put up $10,000 or you're just an obnoxious and worthless kibitzer.

Lumo said...

I didn't fail to obtain any job in physics. I got a job out of 66 applicants and resigned after three years because the university where I worked was taken over by fucking feminist bitches and environmentalist loons and my field began to be publicly attacked by anonymous human shit like you.

I don't believe that you're at CERN but even if you're at CERN, it won't change anything about your being a piece of cowardly immoral human shit and I just don't want to have anything positive to do with this shit. If people like you are at CERN, that's really bad.

Anonymous said...

Lubos, Lubos, Lubos why did you have to bring this upon yourself? Read again De Bunker's early comments: he sounds like a perfectly nice guy who was having fun with his betting websites and not offending anybody. But you had to pour your shit on him, and look what happened: you are left bruised and whining and looking like a loser. When you win your ten grands from Jester you might consider investing some of it in some anger-management course, it will do you good. Besides, what sort of guy quits his job because he's publicly attacked by human shit? Wouldn't that have been one more reason to fight on?

Josh said...

De Bunker, I agree with your comments about the bet. Personally a good bet would be $10k to whoever is right from the other party. Yes that makes the odds 50/50, and the point that Jester is trying to prove is mitigated (since he's not 'technically' taking a big a risk as he is now), but I suspect Lubos wouldn't take the bet in that event.

And Jester seeems like the type to not rob someone blind by forcing a bet where he's pretty much guaranteed to win! ;)

Alejandro Rivero said...

Really all these bets have some ambiguity. For instance, "Will the LHC discover that there are more than 4 spacetime dimensions?", seems to refer to Bulk dimensions, but what about metric dimensions seen as particles? Should a discovery of a Kaluza Klein higher mode count as an extra dimension? (it is a metric dimension, but not space time really, isn't it?)
Same about "Is the universe Supersymmetric?". As formulated, it would include even my own crackpottery (hep-ph/0512065, 0710.1526) wheel. It should be a bet only about the discovery at LHC of elementary scalar particles having the same charge that quarks and leptons.

Anonymous said...

I just have one question:

LHC same as THC?