Time for a Poll: Higgs Mass Prediction

[jgraber]

What mass will the lightest Higgs found in the next three years have?

No Higgs found in next three years,
Below 114 GeV
114-130 GeV
130-150 Gev
150-180 GeV
180-220 Gev
220-360 Gev
Above 360 GeV

Notes:
1. MSSM Higgs predicted less than 130 GeV, non supersymmetric SM Higgs probably higher.
See the graph in this post in Tomasso Dorigo’s blog. http://qd.typepad.com/6/2005/06/a_new_top_mass_.html

2. Below 114 Gev supposedly already excluded by LEP results.

3. Top Mass around 175 GeV

If you have a reason for your vote, please explain it briefly.

I hope many people vote, so I have set the poll to close in 60 days.

We need to reopen or repost the poll in about a year and a half or so, when
LHC starts to take real data.

 

[turbo]

If mass is conveyed by the Higgs boson and gravitational attraction is mediated by the gravitational field (perhaps with gravitons), then both the Higgs field and the gravitational field must be perfectly congruent everywhere in the Universe, or the Universe would not behave consistently. The need for this incredible fine-tuning to explain what we observe argues strongly against the existence of the Higgs, and for the concept that mass, gravitational attraction, and inertia all arise from matter's interaction with a single field. Einstein tried to determine the nature of this field in his search for a GR ether in the 1920's and thereafter, and Sakharov revisited this idea in the 1960's, positing that these qualities of matter arose from matter's interaction with the vacuum in which it is embedded. More recently, Haisch, Rueda, and Puthoff have been following this line of thought, and even Thanu Padmanabhan has revived it, although with a static vacuum that admits of no polarization and thus cannot be dynamical. A background independent theory of quantum gravity cannot arise from a theory with a static vacuum, so there is more to be done. Anyway, I do not believe the Higgs boson will ever be found.

 

[Severian]

Any mass term that you can write down for the electron will break SU(2). Since I believe in gauge symmetry, I believe SU(2) should be a local symmetry at high energies, so the symmetry must be dynamically broken. Therefore, there must be an object (not necessarily fundamental) which couples the left handed fermions to right handed ones, so that it can give an effective mass term when it gains an expectation value. I see no other way around this, so I am sure that the Higgs boson will exist (though it may not be fundamental).

The fine tuning problem is elegantly removed by supersymmetry, so I predict a Higgs mass below 130GeV but above the 114GeV LEP limit.

 

[vanesch]

I guess all your "MeV" must be "GeV" ?

What mass will the lightest Higgs found in the next three years have?

No Higgs found in next three years,
Below 114 MeV
114-130 MeV
130-150 Mev
150-180 MeV
180-220 Mev
220-360 Mev
Above 360 MeV

Notes:
1. MSSM Higgs predicted less than 130 MeV, non supersymmetric SM Higgs probably higher.
See the graph in this post in Tomasso Dorigo’s blog. http://qd.typepad.com/6/2005/06/a_new_top_mass_.html

2. Below 114 Mev supposedly already excluded by LEP results.

3. Top Mass around 175 MeV

If you have a reason for your vote, please explain it briefly.

I hope many people vote, so I have set the poll to close in 60 days.

We need to reopen or repost the poll in about a year and a half or so, when
LHC starts to take real data.

 

[jgraber]

Poll needs fixing

I guess all your "MeV" must be "GeV" ?

Sorry, you're absolutely right.
I have edited the text, but I don't know how to edit the poll.
Jim Graber
If I can't figure out how to fix it, maybe I'll put up a separate corrected version.

 

[jgraber]

Sorry, you're absolutely right.
I have edited the text, but I don't know how to edit the poll.
Jim Graber
If I can't figure out how to fix it, maybe I'll put up a separate corrected version.

Edit: Thanks to moderator Evo for fixing the poll.

 

[vanesch]

I voted in all ignorance "no Higgs found" because at least, that would be something genuinely new and unexpected!

 

[arivero]

something genuinely new and unexpected!

In a recent poll there was the option
"something not in the above, that must surprise everybody"

And I was left thinking about the option "something not in the above list, that must surprise nobody"

 

[arivero]

I voted for 114-130 given a series of rational and irrational motivations.

The most rational one are the plots of compatibility with the standard model. While I believe (now) in supersymmetry, I do not believe in the kind of supersymmetry we are being told to look for.

A step away rationality are the events during the closing days of the LEP, pointing to 115 GeV.

A mile away, this plot:
http://dftuz.unizar.es/~rivero/research/NZ.jpg
that shows that the plot of known beta-intestable nuclei (in turn, related perhaps to the distribution of for uranium disintegration products) peaks for nuclei having the same mass than the W particle. That, and other suggestions, induced me to believe that the extreme cases of nuclear unstability are able to feel the mass of heavy particles (an unlikely thing, giving the many-to-one combination of degrees of freedom). And the areas of 115, 175 and 246 GeV appear clearly in any model of nuclear stability, see for example here overposed on four different models:
http://dftuz.unizar.es/~rivero/research/uno.gif

(note that these plots, honoring nuclear physics, have the units in "amu" instead of "GeV". The conversion is obvious and even Google is programmed to do it)

 

[humanino]

I voted for 114-130 as well, the main reason for me being the constraints from supersymmetry. It would of course be much more exciting if the Higgs is not found, but it would also be a political disaster for founding...

A mile away, this plot:
http://dftuz.unizar.es/~rivero/research/NZ.jpg
that shows that the plot of known beta-intestable nuclei (in turn, related perhaps to the distribution of for uranium disintegration products) peaks for nuclei having the same mass than the W particle. That, and other suggestions, induced me to believe that the extreme cases of nuclear unstability are able to feel the mass of heavy particles (an unlikely thing, giving the many-to-one combination of degrees of freedom). And the areas of 115, 175 and 246 GeV appear clearly in any model of nuclear stability, see for example here overposed on four different models:
http://dftuz.unizar.es/~rivero/research/uno.gif

I'm sorry, I do not quite follow what is shown here. Could you provide more details please, it seems interesting Are you suggesting that these plots are hints for a "light" Higgs ? They do not look like experimental plots : how were they produced ?

 

[humanino]

[...] both the Higgs field and the gravitational field must be perfectly congruent everywhere in the Universe, or the Universe would not behave consistently [...] the concept that mass, gravitational attraction, and inertia all arise from matter's interaction with a single field [...]

Those considerations are very interesting, but a little too "poetic" for my taste. This is very qualitative, and comes merely from vague analogies. I would like to remind that ordinary mass around us does not even care for the Higgs boson : it is hadronic, in the glue field. The infamous problem of the mass gap is a mathematically well defined one, at least as interesting as the quantification of gravity, with $1M for its solution, but it is maybe too difficult to be addressed by average theoreticians... Very unfortunate in my opinion that so many people spend so many time on the same topics...

 

[gjshep]

If mass is conveyed by the Higgs boson and gravitational attraction is mediated by the gravitational field (perhaps with gravitons), then both the Higgs field and the gravitational field must be perfectly congruent everywhere in the Universe, or the Universe would not behave consistently. The need for this incredible fine-tuning to explain what we observe argues strongly against the existence of the Higgs, and for the concept that mass, gravitational attraction, and inertia all arise from matter's interaction with a single field. Einstein tried to determine the nature of this field in his search for a GR ether in the 1920's and thereafter, and Sakharov revisited this idea in the 1960's, positing that these qualities of matter arose from matter's interaction with the vacuum in which it is embedded. More recently, Haisch, Rueda, and Puthoff have been following this line of thought, and even Thanu Padmanabhan has revived it, although with a static vacuum that admits of no polarization and thus cannot be dynamical. A background independent theory of quantum gravity cannot arise from a theory with a static vacuum, so there is more to be done. Anyway, I do not believe the Higgs boson will ever be found.

Nice summary, thanks! Do you know where I can find a reference list of single-field theories? So far W.F Hagen's work on nuclear energiewirbel seems to offer the most promise.

 

[turbo]

Nice summary, thanks! Do you know where I can find a reference list of single-field theories? So far W.F Hagen's work on nuclear energiewirbel seems to offer the most promise.

I don't know if there is a comprehensive listing anywhere, but you might want to chase down Padmanabhan's papers (if you Google his last name, you'll find his home page) and use Citebase to track back to Sakharov's papers, then find out which authors have cited those papers. That type of searching will lead you into some interesting areas - remember that papers can be cited for a number of reasons, and often you will find citations pointing out theoretical problems, conflicts with observation, etc. Good luck.

 

[arivero]

I'm sorry, I do not quite follow what is shown here. Could you provide more details please, it seems interesting Are you suggesting that these plots are hints for a "light" Higgs ? They do not look like experimental plots : how were they produced ?

First, note that this was the far far far far fetched argument of my list.

The plots you see are theoretical models to predict the mass of nucleons. State-of-art mass formulae, if you wish. Because of the complications of the strong force, all these models still use/need empirical parameters. For instance more spin-orbit terms are introduced to alter the shell model plain prediction and then its value is adjusted to fit predictions. So the model has, say, one or two dozen of free parameters and then it is used to predict the masses of some hundreds of known nuclei. No bad.

The point is, they also predict the proton and neutron "driplines", the lines such that beyond them it is not possible to add a neutron or a proton. These are the lines yoy see in the plots and that, specially for the neutron dripline, present irregularities. Then antidiagonally I have traced the "isobars", the lines joining nuclei with equal mass.

The conjecture was that nuclear stability could feel the onset of new particles. This was motivated, as I told, by the coincidence between the mass of W and the huge quantity of beta disintegrations recorded in nuclei having the same mass than W. And becaues I examined the plots and I saw that the antidiagonal of 175 GeV was clearly distinguished. Then another two ones, at 246 GeV and about 115 GeV seem to hint for particles or some kind of QFT effect at these energies. Still, it could be a coincidence (two, actually, the W and the top) and everything being just an artifact of the shell model that every nuclear model mimics.

From these plots my bets should be: something at 115, something at 246 (sqrt(2) top), and something -a charged boson?- perhaps low at 69 GeV. I myself would not put a lot of money on it.Ah, remember the plots are in atomic mass units. 1 amu = 0.931 GeV

 

[jgraber]

Big Surprise!

I am very surprised at the results of this poll so far. I expected the 114-130 GeV category would be the overwhelming winner, for two reasons:
first, experimental evidence indirectly supporting a light Higgs, and
second, theoretical preference for an MSSM Higgs.

Instead this 114-130 category is running second, with No Higgs found the clear leader. I almost left that category out. So lots of people are expecting or hoping for a No Higgs revolution.
A year or so ago, I was definitely an MSSM fan. Now, I am thinking about just a standard model Higgs, perhaps similar to Tommaso Dorigo, in his bet with Jacques Distler and Gordon Watts.
http://physicsweb.org/articles/world/19/12/7/1
http://dorigo.wordpress.com/2006/09/04/this-1000-says-there-aint-new-physics-at-the-tev-scale/
http://dorigo.wordpress.com/2006/09/06/the-bets-are-on/

(Perhaps I can invite them to vote or comment)
But I don’t know where this SM Higgs will show up. Maybe it will also be light. Maybe it will be up near the Top Mass, so perhaps I will vote for 150-180 GeV. Norman voted for 180-220 GeV, but didn’t explain his vote. I’m dying to know why he picked that mass range.
Thanks for voting. Ask all your friends to vote.
Best to everyone.
Jim Graber

 

[arivero]

Well, note that the answer is "No Higgs found in next three years". Now I wonder how many of the "no higgs" people had voted "No Higgs ever" too. And how about the theoretically impossible question "No Higgs, No New Physics, No experimental failure" (There was a 10% vote on "nothing found" in a experimental lab, and I do not know if it was theoretical pessimism or experimental pessimism".

 

[turbo]

Those considerations are very interesting, but a little too "poetic" for my taste. This is very qualitative, and comes merely from vague analogies.

Let me clarify a bit. We currently have a model in which mass is conferred upon matter by the Higgs boson - carrier particle for the Higgs field. We also have a separate gravitational field that mediates the attractive force between these now-massive lumps of matter (whether or not the gravitational field is simply the mathematical model of curved space-time or whether there must be a graviton acting as a carrier particle). In this model, there are two different fields required before we can see gravitational behavior. Naively, we should expect that these fields are dynamic and they can exhibit not only evolution but polarization as they interact with matter. We do not see this, even when we look back a significant percentage of the age of the universe. This implies that either the Higgs field and the gravitational field are congruent to the nth degree everywhere we can observe OR that mass, gravitation and inertia arise from matter's interaction with a single field. I prefer the latter interpretation with no Higgs boson and no graviton. For Einstein's thoughts on this (On the Ether, 1924):

But even if these possibilities should mature into genuine theories, we will not be able to do without the ether in theoretical physics, i.e. a continuum which is equipped with physical properties; for the general theory of relativity, whose basic points of view physicists surely will always maintain, excludes direct distant action. But every contiguous action theory presumes continuous fields, and therefore also the existence of an 'ether'.

I think it is time to revisit Einstein's ideas and give them a fair consideration. I don't think he was wrong in this regard, just ignored, as people grabbed his mathematical approximation of curved space-time and rejected his quest for an extension of GR that would explain the mechanics of gravitation and inertia and encompass EM.

 

[turbo]

Well, note that the answer is "No Higgs found in next three years". Now I wonder how many of the "no higgs" people had voted "No Higgs ever" too.

You're right, but the option of "no Higgs ever" was not available. I would have gone for that one.

 

[Kea]

The option of "no Higgs ever" was not available. I would have gone for that one.

So would I.

 

[arivero]

So would I.

To clarify: what about the opticn

"No Higgs, No New Physics, No experimental failure"

or its equivalent

"I do not believe the unitarity argument".

Any votes here?

 

[Severian]

Well, note that the answer is "No Higgs found in next three years".

Oh, I hadn't realized that. 3 years is pushing it a bit then. I might have voted 'no Higgs in three years' if I had noticed.

I don't think we will have a proper physics run until 2008 and then only 3/fb for the first year, with maybe 10/fb the second. Even if we are generous and say 20/fb by 3 years from now, that might not be enough for the SM Higgs (depending on the mass).

"I do not believe the unitarity argument".

Any votes here?

That would be completely perverse. Something would have to happen to WW scattering.

 

[Kea]

what about the opticn
"No Higgs, No New Physics, No experimental failure"?

Clearly this is nonsense. I wouldn't bet 'no Higgs' if I didn't have some new physics in mind. However, to be precise, what the LHC will or will not see is a different question to the question of 'new physics'.

The thing I don't understand, arivero, is: if you're not a fan of MSSM, which I don't believe you are, then why are you betting on just such a Higgs? Why not t \overline{t} condensates or something like that?

 

[arivero]

Why not t \overline{t} condensates or something like that?

My supersymmetry model depends on the top not being able to bind with other particles, so I am very very sorry I must rule out this kind of condensate . At this moment, I have no theoretical position on the Higgs. Experimentally, if you consider both the 115 GeV deviation and the 3-sigma charged neutral at 69 GeV, then we are speaking at least of a non minimal structure, not very compatible with SUSY neither.

 

[arivero]

That would be completely perverse. Something would have to happen to WW scattering.

Hmm yeah, probably to see WW collide and disappear into nothing would be accounted as New Physics. So "No Higgs, No New Physics, No experimental failure" is an stronger statement about the aproximation being wrong.

 

[humanino]

Let me clarify a bit.

Thank you for your clarifications. Your views are quite interesting really. I am sorry not to be very convinced however, at least not yet. GR tells me that energy attracts energy. Massless stuff is subject to gravity as well.

I find it too naive to think that the Higgs, be it fundamental or a scalar condensate, should be directly linked to gravitational phenomena. I could live in a world without weak interactions, there would be no Higgs mass, and there would still be gravitation. There would also be hadronic masses...

On the other hand, it is true that something like the Higgs appears in Connes' NCG. Maybe this is what Kea has in his mind (I would be grateful if Kea could expose his views here )

 

[vanesch]

This is maybe slightly off-topic, but I wonder what is the obsession with supersymmetry. Granted, it is a *possible* symmetry in nature, but up to now, it is an entirely speculative construction. We never did that before: introduce a symmetry *without any empirical justification*. I don't know really what it brings in. True, there are a few (IMO weak) arguments for supersymmetry, such as the small correction to the evolution of the coupling constants so as to make them coincide at 10^15 GeV or so, and a few other resolutions of "fine tuning" problems. But on the other hand, supersymmetry introduces also several new problems (in the first place, the need for a spontaneous breaking of it, with its own, new, problems, and miriads of new particles and free parameters).

Personally, with what I know about it (which is, granted, not much) I will only believe in supersymmetry when it is firmly experimentally established and I have no choice. So, apart from band-wagon arguments, what is the reason serious people consider supersymmetry so strongly ?

 

[humanino]

Personally, with what I know about it (which is, granted, not much) I will only believe in supersymmetry when it is firmly experimentally established and I have no choice. So, apart from band-wagon arguments, what is the reason serious people consider supersymmetry so strongly ?

If I remember correctly, you vanesh are an experimentalist. Maybe I am wrong, but it is true that, being myself an experimentalist, I share your feeling on supersymmetry.

I however have the feeling that theoreticians love supersymmetry for esthetical reasons mainly. Not even mentionning superstrings, already from the MSSM. I am not going to attempt to list those reasons here, because there are so many, I am sure you know them better than I do and they can be found so easily.

 

[arivero]

what is the reason serious people consider supersymmetry so strongly ?

a perfect question. You are not asking why we the people in the forum would consider supersymmetry, but why the mainstream physicists do.

 

[Severian]

This is maybe slightly off-topic, but I wonder what is the obsession with supersymmetry. Granted, it is a *possible* symmetry in nature, but up to now, it is an entirely speculative construction. We never did that before: introduce a symmetry *without any empirical justification*.

It is a bit stronger than that. It is the only way to enlarge the symmetry group of space-time. It is the natural extension of the Poincare symmetry, and there is definitely a prejudice that the laws of physics come from symmetries. So having space-time as symmetric as possible is definitely attractive. Even if you don't believe in low energy supersymmtry, it is very hard to live without high energy supersymmetry.

True, there are a few (IMO weak) arguments for supersymmetry, such as the small correction to the evolution of the coupling constants so as to make them coincide at 10^15 GeV or so, and a few other resolutions of "fine tuning" problems.

The hierarchy problem is really a big deal for the SM. Essentially, as soon as youy introduce new physics of any kind, the model becomes inconsistant. On its own it is fine, but we know it doesn't describe gravity and there is probably some new physics at some unification scale. Supersymmetry is not the only solution, but is probably the most elegant.

But on the other hand, supersymmetry introduces also several new problems (in the first place, the need for a spontaneous breaking of it, with its own, new, problems, and miriads of new particles and free parameters).

That is not a fair criticism. Breaking supersymmetry is actually rather easy, so it is not an unreasonable thing to expect. The reason the models look a mess is simply because we don't know the mechanism of the breaking, so just parameterise it in a general way. Once the mechanism is known, the theory becomes quite predictive, with very few parameters.

Also, there are very few new fields. The fields are promoted into superfields and the new 'particles' are just us looking at the old SM particles from a different direction (literally!). We can hardly blame the theory for our defective way of experiencing it.

 

[Jheriko]

I voted no Higgs... I just don't like the idea of Higgs particles/fields... seems like a cop-out explanation to me.

 

[vanesch]

It is a bit stronger than that. It is the only way to enlarge the symmetry group of space-time. It is the natural extension of the Poincare symmetry, and there is definitely a prejudice that the laws of physics come from symmetries. So having space-time as symmetric as possible is definitely attractive. Even if you don't believe in low energy supersymmtry, it is very hard to live without high energy supersymmetry.

This is the kind of argumentation to which I'm rather insensitive. There are many possible symmetries in nature which simply do not turn out to be there, and there's no "principle of maximum symmetry" as far as I know. If it were the case, we wouldn't have CP violation, or even parity violation ; SU(5) would obviously be a better gauge theory than U(1) x SU(2) x SU(3)...
There are so many "missed occasions" in nature to have a certain symmetry that I don't think that it is justified, just because it is not impossible, to introduce a symmetry, just because it is a possibility. It's not excluded either of course and we should entertain the possibility of its existence.

I'm also not very sensitive to all those hierarchy and fine tuning "problems". To me, there is no qualitative difference between the real numbers between 1+10^(-20) and 1+10^(-15) on one hand, and 1.5 - 50.0 on the other hand. If it is a free parameter, it is a free parameter and it can just as well be part of the former interval as the latter. With a suitable mapping, we can get the former interval on the latter. It is IMO just psychological that we find the former "hard to believe" and the latter "normal free parameters".

That is not a fair criticism. Breaking supersymmetry is actually rather easy, so it is not an unreasonable thing to expect. The reason the models look a mess is simply because we don't know the mechanism of the breaking, so just parameterise it in a general way. Once the mechanism is known, the theory becomes quite predictive, with very few parameters.

Well, the day that there is a serious mechanism proposed, just a few parameters, and hard predictions, I might change my mind . But for the moment, the non-existence of a precise proposition of its mechanism of breaking allows one to introduce so many "free fit parameters" that one can morph it onto any set of experimental data.

Personally, I have the impression that the main success of supersymmetry is that it allows for easier computations in quantum models, because of the many cancellations that occur. Just make your theory supersymmetric, and you have better chances to have it computable. Whether that is a strong argument for a physical property, I don't know. Classically, integrable systems are also easier to consider. But most classical systems just aren't integrable.

Now, I'm taking some serious risks here, because I might have to eat my hat in a few years, when the LHC spits out superpartners with dozens. But for the moment, I don't bet on it.

EDIT: I must maybe soften my propositions a bit. It is probably because of ignorance that I don't see the compelling reason to almost assume supersymmetry as established, and just waiting for a kind of formal validation by experiment about which one hasn't much doubt. I simply haven't seen this reason yet, and maybe if I were to delve more deeply in its formalism, I might be convinced.

 

[arivero]

... the SM. Essentially, as soon as youy introduce new physics of any kind, the model becomes inconsistant. On its own it is fine, but we know it doesn't describe gravity and there is probably some new physics at some unification scale. Supersymmetry is not the only solution, but is probably the most elegant.

A N=8 gravity supermultiplet has 112+16=128=4*32 fermionic states. The Standard Model has 96+0=3*32 fermionic states. It seems to me that the Standard Model already has got to be at least a 75% of the final answer

More: considering that (112+16)-(96+0)=16+16, I'd say that the problem is to get rid of, or to explain or to predict, only 8 extra unwanted particles of spin 3/2. Of course, if you are in the orthodox way.

 

[Severian]

This is the kind of argumentation to which I'm rather insensitive. There are many possible symmetries in nature which simply do not turn out to be there, and there's no "principle of maximum symmetry" as far as I know. If it were the case, we wouldn't have CP violation, or even parity violation ; SU(5) would obviously be a better gauge theory than U(1) x SU(2) x SU(3)...
There are so many "missed occasions" in nature to have a certain symmetry that I don't think that it is justified, just because it is not impossible, to introduce a symmetry, just because it is a possibility. It's not excluded either of course and we should entertain the possibility of its existence.

The symmetries that you mention are all internal symmetries - not symmetries of space-time. Of course, no-one is saying that supersymmetry must exist just because it can, but it is a very attractive possibility, aesthetically speaking.

I'm also not very sensitive to all those hierarchy and fine tuning "problems". To me, there is no qualitative difference between the real numbers between 1+10^(-20) and 1+10^(-15) on one hand, and 1.5 - 50.0 on the other hand.

But that is not the problem. The problem is that the natural mass of the Higgs boson is the new physics scale, so if new physics appears at the Planck scale, the SM predicts the mass of the Higgs boson to be the Planck mass. But this is in contradiction with the requirement that the Higgs mass be less than about 700GeV to maintain unitarity. The issue is not that 10¹⁹ is a big number, it is that 10¹⁹ is a big number when compared to 700. No amount of (linear) remapping is going to change that.

It is IMO just psychological that we find the former "hard to believe" and the latter "normal free parameters".

No, it is a technically well defined problem. The phase space volume of allowed parameters is much much bigger than the phase space volume of allowed observables (before restricting the observables by measuements).

Well, the day that there is a serious mechanism proposed, just a few parameters, and hard predictions, I might change my mind . But for the moment, the non-existence of a precise proposition of its mechanism of breaking allows one to introduce so many "free fit parameters" that one can morph it onto any set of experimental data.

There are such mechanisms. For example, the constrained MSSM sets up the GUT values as would be compatible with supergravity models, and then has very few parameters, and makes hard predictions (which are getting close to being ruled out in fact).

Personally, I have the impression that the main success of supersymmetry is that it allows for easier computations in quantum models, because of the many cancellations that occur. Just make your theory supersymmetric, and you have better chances to have it computable.

That is not true. Supersymmetry does not make low energy phenomenological calculations easier (except one or two rather specific 'maximal helicity violating' multiloop processes). In fact it makes tham more difficlut because you have to calculate more diagrams. What it does do is make the results more palatable.

Of course, whether or not one likes SUSY is really an aesthetic choice, since there is no evidence for it yet. I happen to believe that the problems it solves are bigger problems than the problems it introduces, so aesthetically supersymmetric models are more pleasing. But it is equally valid to hold the contrary view.

 

[arivero]

The symmetries that you mention are all internal symmetries - not symmetries of space-time. Of course, no-one is saying that supersymmetry must exist just because it can, but it is a very attractive possibility, aesthetically speaking.

But the point was to bypass Coleman-Mandula. If we still have internal symmetries factores out, we have not bypassed the theorem.

 

[Haelfix]

I'm a big believer in GUTs (myriad reasons, including the favored explanation of a nonadhoc seesaw mechanism to set the neutrino masses to experimentally verified values, as well as leptogenesis concerns). Susy helps to make GUTs possible, ergo i'd be very surprised if we didn't see it at some scale. In a related way, its also one of the very few ways to evade Coleman-Mandula and solve the hierarchy problem. There just isn't very many other possibilities.

 

[vanesch]

But that is not the problem. The problem is that the natural mass of the Higgs boson is the new physics scale, so if new physics appears at the Planck scale, the SM predicts the mass of the Higgs boson to be the Planck mass.

This is what I don't understand. Given that the standard model doesn't deal with gravity at all, and given that it might probably need an entire paradigm change in order to include gravity, I don't see how the "planck scale" can pop out of the standard model or any other particle physics model given that it doesn't contain anything related to gravity. How does this "Planck mass" come into play here ? What's wrong with "new physics" at 20 TeV, say ?

 

[Kea]

On the other hand, it is true that something like the Higgs appears in Connes' NCG. Maybe this is what Kea has in his mind.

When Kea voted no Higgs, she was disagreeing with Connes, who is predicting a Higgs boson.

 

[Haelfix]

Err so how do you explain WW scattering? There aren't many alternatives to a higgs like mechanism, the only others I am aware off are riddled with phenomenological problems or are now safely ruled out.

 

[jgraber]

Whatever happened to the old GUTS?

I'm a big believer in GUTs (myriad reasons, including the favored explanation of a nonadhoc seesaw mechanism to set the neutrino masses to experimentally verified values, as well as leptogenesis concerns). Susy helps to make GUTs possible, ergo i'd be very surprised if we didn't see it at some scale. In a related way, its also one of the very few ways to evade Coleman-Mandula and solve the hierarchy problem. There just isn't very many other possibilities.

Since you're a big believer in GUTS, I will ask you a question I was thinking of making into a thread of its own:

Whatever happened to the old GUTS like SO(10), SU(4)xSU(4) and
Flipped SU(5)xU(1)?
As I remember it, these were the three leading contenders once SU(5) was ruled out. You never hear much about them these days. I understand that these GUTS can be included in the SO(32) and E(8)xE(8) that emerge from string theory and so subsumed as part of string theory. Still the bottom level or the level one up from the standard model seems important.
So I will ask a more detailed question related to the current thread:
Will the Higgs mass, or anything else we are likely to see at LHC, help us to distiguish between these three possibilities, or any newer ones?
Curious minds want to know.
TIA
Jim Graber

 

[CarlB]

This is the kind of argumentation to which I'm rather insensitive. There are many possible symmetries in nature which simply do not turn out to be there, and there's no "principle of maximum symmetry" as far as I know. ...

I love this post, (#31).

 

[arivero]

An argument FOR supersymmetry:

taking
d1^ , d2^ = neutrals
d+^ = charged +1, uncoloured
dr^, dg^, db^: colured, and charge -1/3we build:
1 fermion, |0>

6 bosons:
d1, d2, d+, dr, dg, db

15 fermions: as they appear in 5 and 10 of su(5) too
d1^d2, neutrino
d1^d+, positron
d1^dr, d1^dg, d1^db, three d-type quarks

d2^d+ the other degree of freedom of the positron
d2^dr, d2^dg, d2^db, the other three dof for the d-rype quark
d+^dr, d+^dg, d+^db three for the quark up
dr^dg, dr^db, dg^db three for anti-up.

20 bosons, a pretty mess:
d1^d2^d+, d1^d2^dr, d1^d2^dg, d1^d2^db
d1^d+^dr, d1^d+^dg, d1^d+^db
d1^dr^dg, d1^dr^db, d1^dg^db
d2^d+^dr, d2^d+^dg, d2^d+^d2^db
d2^dr^dg, d2^dr^db, d2^dg^db
d+^dr^dg, d+^dr^db, d+^dg^db
dr^dg^db

15 fermions, the oposite ones, in 10 + 5
d1^d2^d+^dr, d1^d2^d+^dg, d1^d2^d+^d2^db
d1^d2^dr^dg, d1^d2^dr^db, d1^d2^dg^db
d1^d+^dr^dg, d1^d+^dr^db, d1^d+^dg^db
d1^dr^dg^db
d2^d+^dr^dg, d2^d+^dr^db, d2^d+^dg^db
d2^dr^dg^db
d+^dr^dg^db

6 bosons
d1^d2^d+^dr^dg, ^d1^d2^d+^dr^db, ^d1^d2^d+^dg^db
d1^d2^dr^dg^db
d1^d+^dr^dg^db
d2^d+^dr^dg^db

1 fermion

d1^d2^d+^dr^dg^db

 

[humanino]

When Kea voted no Higgs, she was disagreeing with Connes, who is predicting a Higgs boson.

I am very sorry if I upset her. My appologies. Would she still please provide more details on her thoughts ? I know very little about NCG.

 

[Kea]

Would she still please provide more details on her thoughts?

The Higgs boson is introduced as an effective mass mechanism within the Standard Model. It cannot hope to explain mass generation within a theory of quantum gravity, which by definition must explain mass quantum numbers. So the question of its existence comes down to how far one is willing to extend the SM notion of Observable. What is a particle? Since our approach to QG (which has nothing to do with Connes' NCG) is not based on Symmetry, and since the effective QFT is not computationally gauge field theory, there is no reason whatsoever to think that the old idea of Observability should carry through to a scale where we fully expect New Physics.

 

[Severian]

It cannot hope to explain mass generation within a theory of quantum gravity, which by definition must explain mass quantum numbers.

Why not? The fundamental particles become massless above the electroweak symmetry breaking scale, so there is no mass to explain. You haven't explained why they have particular Yukawa couplings, but that is a different issue.

 

[arivero]

It sounds as the old issue of inertial versus gravitational mass.

 

[arivero]

An argument FOR supersymmetry:

Please refer to http://dftuz.unizar.es/~rivero/research/Newton.pdf for my current view of supersymmetry. Actually, my view three days ago . Page 1 is old stuff, page 2 is newer (to me).

 

[Kea]

Why not?

Quite simply because the Higgs mechanism is not used in the derivation of rest masses.

 

[humanino]

Please refer to http://dftuz.unizar.es/~rivero/research/Newton.pdf for my current view of supersymmetry. Actually, my view three days ago . Page 1 is old stuff, page 2 is newer (to me).

Ah, this clarifies your eariler post #41

I however still do not quite follow your arguments.
In particular, this hits me :

Having supersymmetry to composites helps to explain some features of charged leptons of the standard model. The pion mass if near of the muon mass. [...]

Do you have an explicit link between pion mass and muon mass !? They are not in the same generation (u and d quarks are in the first family, whereas the muon is in the second family), and even more intriguing, the mass of the pion arises from dynamical breaking of chiral symmetry, so if the muon mass is somehow linked to that, this seems big news to me. Are those only speculations ?

 

[arivero]

In particular, this hits me :Do you have an explicit link between pion mass and muon
mass !? They are not in the same generation (u and d quarks are in the first
family, whereas the muon is in the second family), and even more intriguing, the mass
of the pion arises from dynamical breaking of chiral symmetry, so if the muon mass is
somehow linked to that, this seems big news to me. Are those only speculations ?

what you read is what you get. Indeed, speculations. But note we need all the three generations to get the perfect pairing. So from the point of view of susy the pion is not a object exclusive of the first generation.

Page 2 is more orthodox but I have never seen the argument published neither.

 

[tehno]

No Higgs found (gut feelings).