# Results from EPS-HEP 2011

Results from the EPS-HEP 2011 conference that began today are starting to appear. These include the first results making use of most of the 2011 LHC run data. This is a factor of 30 or so more data than that from the 2010 run, which was the source of almost all previous results released by the LHC experiments. Some of the news so far:

• ATLAS pretty much says here that there are no squarks or gluinos below 1 TeV (see page 9). Comparing to analyses of the regions considered mostly likely (see for example here, figure 7) pre-LHC, significantly more than half of the region in which supersymmetry was supposed to appear is now ruled out. Another factor of 10 or so in data should come in during the rest of the 2011/2012 run, which should allow limits to be pushed a bit higher. At this point, it looks like SUSY is on its way out. It will be interesting to see if die-hards insist that the factor of 2 in energy at the next (starting in 2014-5) run will make a difference.
• For results relevant to strings, black holes, extra dimensions, split supersymmetry, and other exotica, CMS has them appearing here, for ATLAS they’re here. No such objects are being seen, with limits being pushed up dramatically from those coming from the 2010 data. Again, it’s going to be very hard to argue that there’s a significant probability that such things will be seen in the rest of this run, or even later ones at full energy.
• CDF results available here say no Higgs between 156 and 175 GeV, D0 exclusion (here) looks like it covers about 160-170 GeV. Fermilab has issued a press release about this, advertising the release of the combined numbers at a July 27 talk. This should also include low mass searches which might provide exclusion above the 114 GeV LEP limit. The press release mentions a “most likely” range of 114-137 GeV for the Higgs mass, and links to earlier Tevatron exclusion limits, but I suspect the 137 number comes from a different source, not a Tevatron direct search result.
• CMS and ATLAS results on the Higgs are to be announced tomorrow afternoon (an early version of the CMS results leaked here). A combination of results from the two camps will be done after the conference, planned to be announced at Lepton Photon 2011 in late August, although a rough guess as to what that will look like should be available just from seeing the two independent results.
• Philip Gibbs is keeping a close eye on this at viXra log.
• Update: Tommaso Dorigo has some more news here: CMS is not seeing the SM violating forward-backward top pair production asymmetry seen at the Tevatron (more about it here).

Update: ATLAS results on the Higgs are 95% exclusion 155-190 GeV and 295-450 GeV. They see a 2.8 sigma excess of events in the 120-140 GeV range.

Update: I just noticed that Matt Strassler now has a blog and is blogging from Grenoble.

Update: Matt Strassler reports from the CMS Higgs combination talk that they exclude 145-480 GeV at the 90% confidence level. Some excess 120-145 GeV, smaller than ATLAS.

So, in summary, it looks like the LHC + Tevatron have pretty much excluded a high mass Higgs, narrowed the possible mass range down to 114-150 GeV or so. No evidence at all of anything but the SM. The big story of the next few months will be to watch and see if a Higgs signal emerges in the last non-excluded region. Or not….

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### 66 Responses to Results from EPS-HEP 2011

1. SA says:

Actually, the new ATLAS data does not exclude much of the parameter space not already ruled out by other experiments (in the case of mSUGRA/CMSSM).

2. Peter Woit says:

Well, the new results rule out a significantly larger region of possible squark and gluino masses than the 2010 data, one that includes the points that various groups were advertising as “most likely”. It’s very easy to find papers arguing that the LHC was likely to see supersymmetry in this region, here’s a couple more:

http://arxiv.org/abs/0907.2589

http://arxiv.org/abs/1011.1246

I’d be curious to see a review of the pre-LHC literature on this, for comparison with arguments likely to be made now about why these masses have to be much higher.

3. asdf says:

So Susy turns out to be crap after all. Makes sense. It cut too deeply against Ocam. I suspect “diehards” will never give up. Not even after 10 years of operation at full power. I think Planck said that progress in physics is made one funeral at the time.

I suspect the Higgs will be excluded. Chiral symmetry breaking and supeconductivity were both explained as scalars initially. Scalars are probably just something we resort to when we can’t understand the microphysics.

You’ll be sure to update tomorow’s Higgs limits Peter?

4. KD says:

I can’t help thinking supersymmetry is so popular because of the name. I mean, who wants to work on ordinary symmetry if we have supersymmetry? If it had been named more modestly, like Fermi-Bose symmetry, perhaps it would have been placed more appropriately.

Same with string theory. “String theory”: boring. “Superstring theory”? Wow! Must be super interesting.

KD

5. dir says:

just wander how fermilab disfavors 137 – 156 gev higgs

6. piscator says:

Seriously. The problem is not that there is no sign of susy, the problem is that so far there is no sign of *any* physics beyond the Standard Model. If a light Higgs is found, then the hierarchy problem remains as a real problem, and something needs to address it. The underlying argument for susy would remain unaffected – and a 1 part in 10^x fine tuning is a lot better than the 1 in 10^32 fine tuning of the Standard Model. This is why the crappest possible outcome would be a light mass Higgs with no signs of new physics – the best way to kill low-energy susy would be a positive signal for technicolour.

7. younghun park says:

piscator
I agree with you. Not finding higgs and SUSY paritcles will threaten the quatum field theory and Gauge theory. Now quantum field theory needs higgs or something like higgs. If we find nothing and no new physics, many physicists will doubt QCD and Electro-Weak theroy. Finding nothing will not only threaten SUSY and superstring theory, but also gauge theory.

8. piscator says:

QCD and electroweak theory seem in pretty good shape, one would hope so given the number of Nobel prizes already awarded for them….and the correctness or otherwise of strings as a theory of quantum gravity will not be determined by results from a TeV scale collider. But for the question of microscopic structure beyond the Standard Model, the LHC is the best hope there is, and we should hope something new does show up.

My understanding is that the absense of something Higgsish at LHC would disprove QFT – Sean Carroll talks about a no-lose theorem. But the replacement (call it QG) must of course reduce to QFT and the SM in the low-energy limit. This is itself hardly shocking, since neither string theory nor LQG is equivalent to QFT. However, QG must reduce to QFT in such a way that the no-lose theorem is evaded, and this I think is not a property of string theory (and I doubt that LQG has a QFT limit at all).

10. Alex says:

Why would not finding a Higgsy thing disprove gauge theory, or even QFT? My take on that always was that it would simply mean that we lose perturbative control around the TeV scale, and it would be hard to explain all the nice electroweak precision observables. But the claim that QFT itself would have to be wrong because of that sounds way too strong to me.
Nonlinear realizations, fine with me.

asdf,

“So Susy turns out to be crap after all. Makes sense. It cut too deeply against Ocam.”

It may not be realized in nature, but why does it violate Occams Razor so much? The susy breaking one needs to introduce in order to get a good light spectrum (if one insists) is sometimes, but not always, a little messy, but the concept of SUSY itself is very simple…

KD,

“I can’t help thinking supersymmetry is so popular because of the name.”

Supersymmetry is popular because it’s a simple concept, can be integrated in renormalizable theories, solves the hierarchy problem, can solve the dark matter problem. Or do you also think gauge theory is so popular because people like pressurized air so much? 🙂

11. Peter Woit says:

Thomas,

No Higgs doesn’t mean QFT is disproved (and LQG or string theory are irrelevant), it just means that the simplest (and in many ways unsatisfactory) way that we know to describe electro-weak symmetry breaking is wrong. Every HEP physicist should be fervently hoping this is the case. If the LHC results showing the standard model works perfectly up into the multiple TeV range are joined with results showing the Higgs mechanism also works perfectly, the future of the subject is in big trouble (i.e. a victim of its own success).

Alex,

Supersymmetry actually is not that simple a concept, the MSSM is a lot more complicated than the SM. Many people have always found it an unattractively complicated idea that doesn’t explain very much, and the LHC is in the process of justifying this point of view….

Perhaps gauge theories are popular because some of them make predictions which are confirmed by experiments? Nah, that’s so 1970ish.

Actually, we already know that QFT is wrong, since it most likely is incompatible with gravity. 🙂 But what I really would like to know if you can explain away the no-lose theorem by just hand-waving a bit about non-perturbative effects. A generation or more of theorists has said that the LHC is guaranteed to find something, or else WW scattering is non-unitary. Were they all mistaken?

Not that I would bet against a Higgs boson at LHC, at least not at even odds. Perhaps at 20:1.

For some reason my link to Sean’s post did not work. Here it is in plain text: http://blogs.discovermagazine.com/cosmicvariance/2011/06/14/why-we-need-the-higgs-or-something-like-it/

13. Alex says:

Peter,

No-one sane would disagree that the MSSM is much more complicated than the SM (I think…), but that’s because of the modesty of the MSSM, right? – it remains willfully ignorant of the source and mechanism of spontaneous supersymmetry breaking. You can’t deny that SUSY as a concept is simple, right? It’s about as complicated as BRST, {Q,Q*} ~ 2P. Now you can gripe about how ugly SUSY breaking for “realistic” TeV scale SUSY is, fine, but I think the distinction should always be made for the sake of clarity.

Peter, our posts crossed. Above response was directed to Alex.

15. Alex says:

I wasn’t explaining it away, isn’t that basically the no-lose theorem? We either observe something “higgsy”, *or* we observe (though a lot less clearly) the loss of perturbarive unitarity, however that may look. I wasn’t claiming that one wouldn’t see anything, just that it wouldn’t deserve the label “higgsy”, but rather “messy” :).

16. Paolo Valtancoli says:

In my opinion, the searches for Higgs and supersymmetry are hopeless. The truth is probably in an orthogonal direction that no one has been able to see.

17. M says:

News from EPS: a higgs at 144 GeV and a anti-Higgs at 350 GeV

18. Peter Woit says:

Alex,

The very general mathematical idea of “supersymmetry” does lead to some amazing things and probably has something to do with reality (in a way we don’t at all understand). But the supersymmetric extension of the SM, even without SUSY breaking, is not at all compelling, it just makes the SM more complicated, with minimal gain. And SUSY breaking is just a disaster. Claiming that “I have this wonderful beautiful symmetry, only problem is it is badly broken and I don’t know how” is really not at all convincing.

19. Alex says:

Peter,

Of course we can argue all day, in the end nature doesn’t care :), and I’m not here to fight the fight for SUSY, really. Just about your last comment, I do not understand your claim that that the supersymmetric version of the SM before SUSY breaking is so complicated. Beyond the unique supersymmetrization of everything, one only needs a second Higgs doublet for three independent reasons (but no second Higgs mass parameter!) and in return we even get rid of the quartic coupling, and the potential quadratic divergence, and that’s it. Do I miss something?

20. Peter Woit says:

Alex,

You’ve doubled the number of degrees of freedom and, at a formal level, supersymmetric field theories are just more complicated beasts to write down precisely and do calculations in. I don’t buy the argument that the MSSM Higgs sector improves the Higgs situation.

If this actually led anywhere, sure, it would be worth it. But all it leads to is the necessity of totally making a worthless mess because you need SUSY breaking.

21. David Pennell says:

http://www.nature.com/news/2011/110722/full/news.2011.435.html “Collider sees tantalizing hint of Higgs” did you already discuss this?

22. Henry says:

Peter,

I am sorry to disappoint you but SUSY is not dead at all. I should remind you that SUSY is not just mSUGRA or some simplified model that’s been used by ATLAS/CMS to extract gluino/squark exclusion limits. You can have for example a compressed spectrum resulting in soft jets / leptons which will easily lower those exclusion curves. Besides 1 TeV is not too high…

23. SA says:

The question about being “most likely” comes from naturalness. The papers you have linked are candidates for detection in the first round of combined LHC-7, XENON-100 data. Specifically, they found models where both the gluino (which the LHC is sensitive to) and the neutralino (which XENON is sensitive) are light. This means that in the case of a null result, they would be the first to be ruled out.

However, the naturalness/fine-tuning parameter relating the (high energy) higgs-mixing mass to the Z pole, can remain small for very large sparticle masses. This means that you should not look to squark-gluino or m_0–m_{1/2} exclusion curves, but instead exclusions in the Higgs sector to rule out SUSY. It is extremely unlikely to have SUSY with Higgs > 140 GeV, whereas gluino and squark masses can be very heavy.

24. Benni says:

I think I remember some private talking to some reowned person working at LHC. He/she laimed that LHC will have good exclusion data for the higgs in the range of 145-120Gev at the end of 2012… but this is just what their group expects…

25. Hi Peter,

Thanks for this very useful post.

It seems that this 2.8 sigma excess could be just background … Let’s see if there is an other end with more stat.
For the SUSY parts, perhaps we should remind ourselves about a low-mass Higgs predicted by SUSY too.

Feel free to answer to me If I have some parts I misunderstand.

Thanks again.
AF

26. Jobs says:

“at a formal level, supersymmetric field theories are just more complicated beasts to write down precisely and do calculations in.”

While I agree with most of what you write here, Peter, the above statement is wrong. Something that has become apparent in the last few years is that, contrary to expectations, supersymmetric theories are significantly *easier* to perform calculations in. In fact the more SUSY a theory has, the “neater” it is, and the easier it is to calculate. Take a look at arXiv:0808.1446, a very instructive and interesting paper.

This doesn’t affect your argument about broken SUSY and the MSSM, which I think is just as messy as it appears. But perhaps we have no right to expect simplicity at low energies.

27. Peter Woit says:

Jobs,

Another way of saying what I was trying to say is that, to calculate things in the SM, you need to read volumes I and II of Weinberg. For any supersymmetric extension of the SM, you need this, and volume III. When there are lots of supersymmetries (N=2 and N=4 theories) you get interesting new ways to do calculations. That’s much less true of N=1, which is the experimentally viable case.

Is calculating g-2 of the electron easier in N=1 super Yang Mills than in the standard model?

Sebastian,

That article is fairly accurate and hype-free from what I can see.

Benni,

I think we’re not going to have to wait till late 2012, maybe more like late 2011…

Henry and SA,

Sure, you can push up the gluino and squark masses as much as you want to evade non-detection at the LHC. But, if you want SUSY to solve various problems it was supposed to solve, you get the sort of predictions that have now been shown to be wrong. For a more general argument, watch Arkani-Hamed’s talk at Strings 2005. He states quite clearly and vigorously that within a year or so of LHC turn-on, we’ll know whether SUSY is relevant to the electroweak scale (exactly because squarks and gluinos should be easy to see in the early data). His prediction has come true and the answer is now in.

One thing I’m curious about is whether Gross and others who were taking bets on SUSY are still willing to take such bets. I suspect they’re not yet willing to pay off, but they’re not about to take any new bets…

28. Mitchell Porter says:

A reminder of why supersymmetry is so popular in physics might be in order. Supersymmetric grand unification produces gauge coupling unification; supersymmetry can protect a light Higgs mass without finetuning; supersymmetry provides dark matter candidates; supersymmetry shows up in unified theories that include gravity. It’s a fairly impressive résumé, so it’s natural that so much effort has been expended in exploring the space of supersymmetric theories, looking for models which realize all the features above.

29. Tobias says:

Isn’t it also true, that sometimes SUSY is introduced to make calculations easier if the result doesn’t actually depend on the SUSY?

30. piscator says:

Jobs:

`apparent in the last few years’? Apparent in the last thirty years would be more apt. It has been known for a long time that the more supersymmetry present the more special the theory is, and I don’t think the paper you refer to adds to this.

Just to be explict for Peter: there are *lots* of computations that are extremely easy to do in theories with N=1 supersymmetry that are *impossible* to do in theories with N=0 supersymmetry. For example, the question ‘does a vacuum of the theory with exactly vanishing vacuum energy exist?’ can be answered in N=1 theories to arbitrary order in perturbation theory with very little work. But I’m sure you know this, so I am puzzled why you are trying to argue to the contrary.

31. Peter Woit says:

piscator,

My argument is really motivated by an allergy to SUSY hype. Sure, there are calculations you can do in SUSY theories you can’t do in non-SUSY theories. But, the technical baggage that comes with SUSY is substantial, and for experimentally relevant calculations in the SM, it’s typically either not useful or less than useful. I’m legitimately curious about whether one can point to uses of SUSY to help with loop calculations in the SM like the electron g-2.

One simple example: one main source of reliable non-perturbative calculations in the SM is lattice gauge theory. There SUSY is worth than useless, adding SUSY to the SM generally changes things from difficult to impossible.

32. Eric says:

Peter,

Yes, supersymmetry helps with loop calculations, the primary example being the loop corrections to the Higgs mass. The effect that supersymmetry has on loop corrections is, in fact, one of the main reasons for theoretical interest in it.

33. Eric says:

Also, supersymmetry can have a strong effect on g-2 of the muon. Corrections to g-2 of the muon have long been looked at as possible evidence for supersymmetry.

34. anon. says:

It’s just not accurate to say that the LHC is excluding gluinos and squarks below 1 TeV. What they are excluding are SUSY spectra in which gluinos and squarks always decay directly to a light neutralino plus jets. Whatever your prejudices are about SUSY models and mechanisms of SUSY breaking, you should appreciate that this is a very specific assumption. If you assume, for instance, that every decay chain always has one extra step — gluino decays to jets plus a neutralino, which in turn decays to another particle or particles and a lighter neutralino, for instance — you will find that the typical limits on gluino masses are lower by at least a couple hundred GeV, and often more, depending on details.

The limits are very strong; the LHC detectors are working remarkably well and the collaborations are making good use of the data. But it is not yet the case that the results exclude new strongly-interacting particles below 1 TeV. The easiest results are getting out first, and these results are not representative of the bulk of SUSY parameter space.

35. Low Math, Meekly Interacting says:

Hi, all,

Without wishing to create a tangent to the argument about the pros or cons of SUSY, SUGRA, or what-have-you, I just have a simple question: Are we now much closer to or at the point that the MSSM has been ruled out?

Thanks!

36. Peter Woit says:

anon.,
But where is the “bulk of SUSY parameter space”? By some measures, it’s off beyond the LHC reach. I’ve been pointing to some of the pre-LHC work I’m aware of by groups trying to give an answer to that question in terms of assumptions that SUSY does various things it is supposed to do, as well as general statements such as Arkani-Hamed’s one at Strings 2005, and these seem to me starting to be in serious conflict with the data. This is not just my opinion, see the last slide of the talk by Rogerson on SUSY fits: “Air is starting to become very thin for these constrained models of SUSY”. If you start relaxing these constraints generically, do you evade the LHC results? Or do you need to start picking specific directions to go in to do this? As an example, is adding steps to the decay chain generic or not?

LMMI,

The problem is that the MSSM has 120 or so extra parameters. You can’t ever rule it out, all you can rule out are parameter ranges, specifically the parameter ranges corresponding to various motivations for the MSSM. If your only motivation is that you like the idea of SUSY, that you like the expected CC to be off by 60 instead of 120 orders of magnitude, or some such, there’s no way to rule this out.

37. anon. says:

see the last slide of the talk by Rogerson on SUSY fits: “Air is starting to become very thin for these constrained models of SUSY”.

The key there being “these constrained models.” In fact mSUGRA and the other similar constrained models being fitted are not even models in any real sense, they’re ansätze chosen to evade flavor problems but not really consistent with any reasonable UV-completion I know of. (Of course, I don’t know any real SUSY model that’s completely free of problems; but at least I know some that are honest models.)

If you start relaxing these constraints generically, do you evade the LHC results? Or do you need to start picking specific directions to go in to do this? As an example, is adding steps to the decay chain generic or not?

If the gravitino is light enough (e.g., in low-scale gauge or gaugino mediation), there is always at least one extra step in the decay chain, and generically this weakens limits quite a bit (although more specific targeted searches recover part of the difference). Another fairly common scenario that can arise in high-scale SUSY breaking models is that instead of getting light quark jets in decay chains, you can get a substantial fraction of tops. Because the top mass is bigger and it has more decay products, these events tend to fail the jets+Met cuts (less missing E_T, lower energy jets). Again, though, targeted top-related searches might still exclude part of this parameter space. More generally, it’s pretty generic to have extra steps, but the decay considered in the ATLAS search, for instance, still happens with some branching fraction. So the limit is weakened by a model-dependent amount.

It’s very hard to make completely general claims. The constraints are very strong and getting stronger; I don’t mean to suggest otherwise. I think there’s cause for at least a little concern (not just about SUSY, but about finding new physics beyond the Higgs at the LHC at all!). Certainly I was hoping there would be some kind of unambiguous new physics showing up by the time we had 1 fb^-1. But, there are still sensible models where the gluino can be in the neighborhood of 500 to 600 GeV without being ruled out, and somewhat more contrived models where it can be quite a bit lighter even than that.

38. Benni says:

yes peter, it was a typo. My source ment late 2011. The sentence should be

He/she laimed that LHC will have good exclusion data for the higgs in the range of 145-120Gev at the end of 2011… but this is just what their group expects…

39. Jobs says:

“My argument is really motivated by an allergy to SUSY hype. ”

This is admirable, but anti-SUSY hype is just as bad as SUSY hype. We should try and be objective.

Regarding supersymmetry being used in SM computations, I can testify that it provides an extremely useful organisation of loop calculations. Indeed, you can separate one-loop amplitudes in QCD into “SUSY parts” and “non-SUSY” parts, and this division is a significant aid to calculation. This says nothing about whether low energy susy exists, but it does point to QFT and SUSY being natural bedfellows.

40. Low Math, Meekly Interacting says:

Hi, Peter,

That’s kind of what I thought, but thanks for clarifying.

41. anonomous says:

What are the chances of finding an attractive alternative to Higgs/SUSY through phenomonology by the end of the year? Is anybody suggesting new settings for the detectors? I am just thinking that if the Higgs is excluded by the end of 2011 there won’t be much data in other areas as the LHC shuts down for the next year.

42. Peter Woit says:

anonomous,

The LHC will run not just through the end of this year, but through the end of next year. The Higgs should keep them busy, either conclusively ruling it out, or studying a real signal.

If the Higgs is ruled out at all masses, there will be a lot of attention on the implications of this, and the question of where the LHC can look that might provide a clue as to what is going on. Maybe different kinds of triggers and searches will get attention, but I’d guess that this would wait until after the machine turns on again at higher energy in late 2014/early 2015.

43. Garrett says:

“One thing I’m curious about is whether Gross and others who were taking bets on SUSY are still willing to take such bets. I suspect they’re not yet willing to pay off, but they’re not about to take any new bets…”

At the last FQXi conference, Frank Wilczek expressed a lot of confidence in SUSY. During the questions after his talk I suggested we place a bet, and he took me up on it. (He’s a good guy, and I respect him a great deal, but we differ in our SUSY confidence.) I figured it would be a typical $1 physicist bet, but he suggested$1K and a six year deadline. I agreed. So now we have a public bet that superparticles will or won’t be seen before July 8, 2015. Max Tegmark is our referee.

There has to be a better way to make money than betting against nobel laureates, and I may lose, but it’s certainly fun.

44. piscator says:

LMMI:

IMO we are a lot closer to the point where the MSSM is ruled out, but not any closer – in fact perhaps further – from the point where low-energy susy is ruled out.

For the MSSM, the required fine-tuning in the Higgs mass looked contrived before the LHC turn on and looks even more contrived now. If the hints of broad excesses in 120-150 GeV in the Higgs search turn out to be true, then things will be even trickier, as to further raise the Higgs mass in the MSSM requires either very heavy sparticles or large trilinear terms, and this all looks terribly ugly and fine-tuned.

However, for supersymmetry in general, this does not hold. From a top down perspective there is diddly squat reason to think that the only new particles nature can have is one Higgs doublet. In models beyond the MSSM it is not hard to raise the Higgs mass and so a Higgs of (say) 135 GeV is not a good reason to reject low energy supersymmetry per se.

The way I see it, the hierarchy problem is real and there is something that solves it. The only two good candidates for this are susy and technicolour (or its modern Randall-Sundrum avatar). If a light Higgs exists – and the EPS results give preliminary hints that it does – then I regard weakly coupled solutions to the hierarchy problem (like susy) as preferred, if not definitively, to strongly coupled solutions like technicolour.

IMO anti-susy partisans need an intelligible opinion on the hierarchy problem – the Higgs mass *is* quadratically divergent in the Standard Model. You either think this isn’t a problem (and if so why not?) or if you do think this is a problem, then you must describe how you will solve it. If you think susy is bad, study the alternatives….

45. Unknown says:

Dear Peter,

You complain about the doubling of degrees of freedom in SUSY but you fail to realize that multiplying by 2 is not the same as adding 50 new particles. After all, doesn’t antiparticles double the number of degrees of freedom? Does that bother you?

Then you say that SUSY QFTs are more complicated. How could this be? They are
as good QFTs as any other but with more symmetry (which means less independent couplings, more predictive power, unexpected cancellations an so on). How could this be more complicated?
If you “don’t buy the argument that the MSSM Higgs sector improves the Higgs situation”, then I’m afraid is hopeless to argue with you at all.

46. Peter Woit says:

Unknown,

This is just ridiculous. Adding SUSY to the SM give you the MSSM (or worse), which has 120+ more parameters than the SM and is vastly more complicated. After 30 years of failure, believing the problem of SUSY breaking can be solved in some simple way that gives a simple, predictive theory is just wishful thinking. With no symmetry breaking, all you have is a theory in violent disagreement with reality, with lots of new symmetries, all of which do nothing but relate degrees of freedom we know about to ones that can’t possibly exist.

Piscator,

The Higgs mechanism seems to me to have more serious problems than the hierarchy problem. Problems with the Planck scale are QG problems we really don’t understand. Before worrying about whether another scale (e.g. the GUT scale) can be stabilized with respect to the weak scale, one should first have evidence for its existence.

Besides the problem of whether a non-asymptotically free theory like the Higgs really makes sense at high energies, the really serious problem is that the Higgs makes it impossible to ever calculate most of the SM parameters. This is really ugly, unlike the rest of the SM, which is a fantastically powerful and beautiful mathematical structure. SUSY doesn’t solve this problem, instead makes it worse.

In any case, first of all the question is whether the Higgs really is there, and it’s very exciting that the next few months might see an answer to this question after so many years.

47. Unknown says:

I guess I’m losing my time arguing with you, but maybe some readers of this blog will benefit after being exposed to your misconceptions.

“…new symmetries, all of which do nothing but relate degrees of freedom we know about to ones that can’t possibly exist.” I beg your pardon, maybe you published some proof of the inconsistency of SUSY?

“Adding SUSY to the SM give you the MSSM (or worse), which has 120+ more parameters than the SM and is vastly more complicated.”
The trees don’t let you see the forest. What you get out of SUSY is the ability of explore experimentally, through the SUSY spectrum, physics at extremely high energies, and it’s difficult to imagine how the hell could you get a similar ability in any other theoretical framework.

“After 30 years of failure,” 30 years of failure are fine as soon as the first superpartner turns up. Let’s talk about failures then.

“The Higgs mechanism seems to me to have more serious problems than the hierarchy problem. Problems with the Planck scale are QG problems we really don’t understand.” Do you find the see-saw mechanism attractive? If you do, you have the Higgs hierarchy problem exploding in your face.

“Besides the problem of whether a non-asymptotically free theory like the Higgs really makes sense at high energies,…” Next time I hear this often repeated B.S. I’m gonna throw up. You’re really concerned about QED then?

“the really serious problem is that the Higgs makes it impossible to ever calculate most of the SM parameters.” Excuse me?

“This is really ugly, unlike the rest of the SM, which is a fantastically powerful and beautiful mathematical structure.” Yeah, like the flavour sector.

Sometimes one wonders if you’re really a particle theorist.