Beyond Standard: what will the LHC find?

[hossi]

What do you think will we discover with the LHC? And what will we learn from it?

Reference:

http://arxiv.org/abs/hep-ph/0602198"

I.e. how realistic do you think is the discovery of extra-dimensions, black holes, supersymmetry, the one more probable than the other, and what if (!) they DONT find the Higgs?

 

[josh1]

what if (!) they DONT find the Higgs?

 

[George Jones]

Since I don't know enough to make an informed guess on what I think is most probable, I voted for what I would like to see discovered - new and completely unexpected physics. For me, this is "the glass is half full" perspective, because this might mean that radical new ideas are needed.

By black holes, do you mean the physics of real black holes, or the physics of dual black holes (e.g., Nastase's interpretation of the RHIC fireball), or either?

How similar are the last 2 choices in the poll, i.e., is finding nothing new (and in particular not finding the Higgs) at all evidence for other physics beyond the standard model?

Regards,
George

 

[Pengwuino]

Is there a "we can't predict the future" option?

 

[marcus]

..."we can't predict the future"...?

that is right, or at least we can't know it.
But we can guess. And soon enough (if LHC starts next year) we will find out which, if any, of our guesses are correct.
I expect you must have predicted that Higgs would be found at LHC, Pengwuino, so in that case we can see if you were right

interesting poll, kudos to Sabine
here are my guesses about who said what

The Higgs 3 60.00% (Pengwuino, josh, me)
Supersymmetry 1 20.00% (josh)
Extra Dimensions 0 0%
Black Holes 0 0%
Other Physics beyond Standard 1 20.00% (george)
Nothing new at all 2 40% (Sabine, me)

total of 5 people voted. some voted twice so a total of 7 votes

 

[Pengwuino]

I don't even know enough to know I am making wild guesses as to what the LHC will find

 

[Orion1]

The Large Hadron Collider (LHC) is a particle accelerator which will probe deeper into matter than ever before. Due to switch on in 2007, it will ultimately collide beams of protons at an energy of 14 TeV . Beams of lead nuclei will be also accelerated, smashing together with a collision energy of 1150 TeV.

This vacuum expectation value (vev) of the Higgs field is constant and equal to 246 GeV.

The Standard Model does not predict the value of the Higgs boson mass.
It has been argued that if the mass of the Higgs boson lies between about 130 and 190 GeV, then the Standard Model can be valid at energy scales all the way up to the Planck scale (10^16 TeV).

Many models of Supersymmetry predict that the lightest Higgs boson (of several) will have a mass only slightly above the current experimental limits, at around 120 GeV or less.

Within the Standard Model, the non-observation of clear signals at particle accelerators leads to an experimental lower bound for the Higgs boson mass of 114.4 GeV at 95% confidence level.

Precision measurements of electroweak observables indicate that the Standard Model Higgs boson mass has an upper bound of 175 GeV at the 95% confidence level as of March, 2006 (using an updated measurement of the top quark mass).

The mass of the Higgs boson lies between 114.4 GeV to 175 GeV at the 95% confidence level as of March, 2006.

The Law of Averages predicts mass of the Higgs boson at 144.7 GeV with 95% confidence level.

However, most theorists expect new physics beyond the Standard Model to emerge at the TeV-scale, based on some unsatisfactory properties of the Standard Model. The highest possible mass scale allowed for the Higgs boson (or some other electroweak symmetry breaking mechanism) is around one TeV; beyond this point, the Standard Model becomes inconsistent without such a mechanism because unitarity is violated in certain scattering processes.

Reference:
http://en.wikipedia.org/wiki/Higgs_boson

 

[arivero]

I have voted The Higgs Supersymmetry Other Physics beyond Standard and Nothing new at all. Acutally, I think we could find the four things.

 

[selfAdjoint]

I voted for Higgs and Other. Higgs because it seems pretty well supported, and Other just as a sort of lark celebrating Lisa Randall's predicted higher dimensional particles (Warped Passages). Oh shucks, I should have clicked on extra dimensions too.

 

[francesca]

Physicists have to hope that LHC will not find Higgs!
New generation needs somethings to work on...
Seriusly, I fear that if Higgs will be found, one wouldn't delve into Standard Model, that is not so "standard" ;-)

 

[marcus]

I have voted The Higgs Supersymmetry Other Physics beyond Standard and Nothing new at all. Actually, I think we could find the four things.

arivero, how do you imagine results from which all those four things can be simultaneously concluded? that would be something interesting!

I take it you mean the logical AND, and not merely the OR of those things you picked

 

[josh1]

...I fear that if Higgs will be found, one wouldn't delve into Standard Model, that is not so "standard"

It sounds like you're saying you'd prefer if current ideas about the standard model are wrong. The goal is to figure out how nature operates, not to create new theories for their own sake.

I have voted The Higgs Supersymmetry Other Physics beyond Standard and Nothing new at all. Acutally, I think we could find the four things.

I'm inferring from the very last remark that you believe the higgs and supersymmetry to be virtually forgone conclusions. If so, I of course completely agree.

 

[marcus]

Physicists have to hope that LHC will not find Higgs!
New generation needs somethings to work on...
Seriously, I fear that if Higgs will be found, one wouldn't delve into Standard Model, that is not so "standard" ;-)

I have heard this from other physicists. I think you are saying that it would be better for the theoreticians if LHC finds no Higgs because it would challenge them to think harder and come up with different ideas.

If that is what you mean, I suspect you are right.

But you say also that you "fear" that seeing Higgs would make the particle theorists too sluggish and complacent.

The image I get is of alligators who have just been fed, basking on a warm rock in the sun. OK guys, the Higgs has been seen, let's all go to the beach!

I would not "fear" this exactly. It would not do any harm and it might be nice for them.

========================

I think new physics when it appears probably has to come from papers like
http://arxiv.org/abs/gr-qc/0604016
http://arxiv.org/abs/hep-th/0512113
where there has been constructed a background independent QFT (no prior metric, Minkowski or other). They have, in a sense, finessed Feynman diagrams out of spinfoams, or vice versa. In a rough preliminary way, QFT has been made to emerge from a QG model of space time and matter as G->0.

So in that view, new physics would in any case NOT from particle theorists inspired by LHC, but would come by spacetimematter theorists RECONSTRUCTING THE STANDARD MODEL ON A NEW more fundamental SPACETIME.

In that case, if particle theorists spend a few years feeling happy that they saw a Higgs, it does not do anyone any harm, no important discoveries are missed that they would have otherwise made.

 

[arivero]

arivero, how do you imagine results from which all those four things can be simultaneously concluded? that would be something interesting!

I take it you mean the logical AND, and not merely the OR of those things you picked

Yep, I mean the AND.

For instance, we could find that the breaking comes from some topcolor mechanism that fakes a Higgs and that diquarks couple to this composite with yukawian couplings equal to the ones of quarks, so we have supersymmetry (diquarks are spin zero), higgs (faked), nothing new (as described) and of course it is Beyond Standard.

I could also suposse that the top condensation is instead due to deconstructed high dimensions (which are fake dimensions, form there the "deconstructed"). The only thing I can not imagine simultaneusly is a black hole. In fact I am intrigued about why it is between the options.

 

[arivero]

The mass of the Higgs boson lies between 114.4 GeV to 175 GeV at the 95% confidence level as of March, 2006.

The Law of Averages predicts mass of the Higgs boson at 144.7 GeV with 95% confidence level.

No, because the distribution is not uniform. Actually it peaks in the low range.

 

[francesca]

looking at "Quantum Gravity and the Standard Model"...

https://www.physicsforums.com/showthread.php?t=113185&page=3

If I understand f-h, it is accepted by (at least some, perhaps all) QG experts that there must be a higgs, and that inertia cannot be the result of how particles couple to the geometry-----and, if I understand him, it is definitely a FLAW in Sundance preon model that it does not predict a higgs.

But in Sundance-Markopoulou paper they open to Higgs or other mechanisms for symmetry breaking in future works...

[...] On a lunch time group vote if we expect the Higgs to be found there was a slight majority for "no". The overall mood is that it'll be far more exciting if we find an alternative mechanism that tells us something structurally new about nature. But I don't think anybody expects that we'll see Quantum Gravity at the LHC instead of the Higgs.
But as I said, this was lunch conversation please don't overrate/quote/take serious. ;)

Sorry h-f ...

Well, who is working on this alternative mechanism now?
excluding Smolin&co, if we accept that

[...] some points of the Sundance paper(s) (are) interesting, but they do not serve for LQG purposes...

----------------
see also:
https://www.physicsforums.com/showpost.php?p=949095&postcount=467

 

[hossi]

By black holes, do you mean the physics of real black holes, or the physics of dual black holes (e.g., Nastase's interpretation of the RHIC fireball), or either?

Hi George,

I was referring to the "real" mini black holes at TeV-scale, that are possible in case the "true" fundamental Planck Scale is not at 10^16 TeV, but close to some TeV, and thus accesible at the LHC.

See e.g.

http://www.sciam.com/print_version.cfm?articleID=000CCC72-2AED-1264-980683414B7F0000"

or this introduction, which lists plenty of further references

http://arxiv.org/abs/hep-ph/0412265"



B.

PS: If you have Lisa's book, she also says some words about it.

 

[meteor]

Maybe it will detect superWIMPS (i.e. the decay products of WIMPS)

 

[Astronuc]

I was referring to the "real" mini black holes at TeV-scale, that are possible in case the "true" fundamental Planck Scale is not at 10^16 TeV, but close to some TeV, and thus accesible at the LHC.

If not black holes, why not "white holes"?

What would happen if a "mini black hole" was created? Is it a transient phenomenon? Could it be 'contained'? What if it 'fell' out of the confinement chamber - would it start sucking up matter around it?

I imagine sometimes, what if one of the objects described as a supernovae or black hole was actually initiated by a group of scientists doing a LHC experiment.

What if the big bang was initiated by an LHC experiment. In that sense, the universe would be like the matrix. Every many billions of years, a civilization is created and it ends up restarting the process.

I know this is wild speculation, but ever since I heard Sheldon Glashow and Steve Weinberg talking about experiments that would shed some light on the beginnings of the universe with the Superconducting Supercollider, I began to wonder "what if they inadvertently created the Big Bang?" Well, we wouldn't be around to wonder about it - for sure.

..."we can't predict the future"...?

that is right, or at least we can't know it.
But we can guess. And soon enough (if LHC starts next year) we will find out which, if any, of our guesses are correct.

Hmmm. At least the guesses are testable - maybe. :uhh:

 

[Hans de Vries]

What about the socalled "pomeron" ?

http://www.cerncourier.com/main/article/39/3/16/1

Regards, Hans

 

[selfAdjoint]

What about the socalled "pomeron" ?

http://www.cerncourier.com/main/article/39/3/16/1

Regards, Hans

Goodness, I had no idea about the Pomeron! Donnachie says some new info on it was expected from the Brookhaven heavy ion experiments. Are you aware of any Pomeron results from there?

 

[Chronos]

I think we need not fear destroying the universe. Nature regularly generates events more energetic than anything the LHC is capable of replicating. I vote for the Higgs. Particle physics is in serious trouble if the Higgs does not make an appearance in the LHC. Given the very good predictive power of the standard model, this would be a fairly shocking non-result.

 

[Hans de Vries]

Donnachie says some new info on it was expected from the Brookhaven heavy ion experiments. Are you aware of any Pomeron results from there?

There seems to be quite some activity. From the proton-proton experiment:

http://arxiv.org/PS_cache/nucl-ex/pdf/0305/0305012.pdf
http://www-ppd.fnal.gov/eppoffice-w/Research_Techniques_Seminar/Talks/Dec2005.ppt


Regards, Hans

 

[wolram]

Maybe the LHC is making particles not finding them, how is it known that any
finding is natural ?

 

[Astronuc]

I think we need not fear destroying the universe. Nature regularly generates events more energetic than anything the LHC is capable of replicating. I vote for the Higgs. Particle physics is in serious trouble if the Higgs does not make an appearance in the LHC. Given the very good predictive power of the standard model, this would be a fairly shocking non-result.

True, I should have thought of that.

Samuel C. C. Ting and others are hoping to investigate some high energy interactions - Alpha Magnetic Spectrometer AMS - http://www.srl.utu.fi/projects/ams/ams.html

I attended a presentation by Ting about AMS last summer. Impressive experiment.

http://hpl3tri1.cern.ch/

http://www.infn.it/esperimenti/esperimentien.php?gruppo=2&sigla_naz=AUGER
The last mentions GCR at 10²⁰ eV.

 

[Chronos]

You are a quick study, as usual, Astronuc.

 

[hossi]

If not black holes, why not "white holes"?

Cause they have to be created.

What would happen if a "mini black hole" was created? Is it a transient phenomenon? Could it be 'contained'? What if it 'fell' out of the confinement chamber - would it start sucking up matter around it?

No, it wouldn't. It makes a Hawking radiation and the temperature is much too large too allow growth. It decays long before it has even hit the detector. Typical lifetime is about 100 fm/c, that's approx 10^-21 seconds. The temperature is about several 100 GeV.

B.

 

[Chronos]

Hossi, wouldn't tiny BH decays in the Earth's atmosphere be detectable by SWIFT, or other current detectors? I sheepishly admit I haven't looked up the specs. But, even a brief burst at such high energies in the Earth's atmosphere would surely be detectable, would it not?

 

[hossi]

Hossi, wouldn't tiny BH decays in the Earth's atmosphere be detectable by SWIFT, or other current detectors? I sheepishly admit I haven't looked up the specs. But, even a brief burst at such high energies in the Earth's atmosphere would surely be detectable, would it not?

Yes, and it would look like a cosmic ray shower.