The Hierarchy Problem: Exploring the Mystery of the Weak and Planck Scales

[cube137]

Some of you may think that the Hierarchy Problem is all about why is the weak scale and Planck scale so far apart or has big difference in energies. And some like Nikkkom may state nature is just like that and there is no problem. But the problem is not that. The consequence of a large Planck mass is the quantum contribution to the Higgs mass would also reach Planck mass.. why it didn't happen is the main motivation of supersymmetry and even the LHC revolves around this Hierarchy Problem. The following gives good intro about it. https://profmattstrassler.com/articles-and-posts/particle-physics-basics/the-hierarchy-problem/ Nikkkom.. if you really understand the Hierarchy Problem.. please explain how you understand it and why you think all physicists are overreacting.

For others. Without Supersymmetry, Extra Dimensions, Multiverse, Scale Symmetry.. what papers or publications have you come across that is likely alternative to the solution to most perplexing puzzle beyond the standard model... the Hierarchy Problem?

 

[nikkkom]

The consequence of a large Planck mass is the quantum contribution to the Higgs mass would also reach Planck mass.. why it didn't happen is the main motivation of supersymmetry

Correct.
Wikipedia has a good article explaining it in some details: https://en.wikipedia.org/wiki/Hierarchy_problem

The thing is, not only supersymmetry can be a solution. Other solutions are already proposed (see wiki), and even more can be discovered in the future. If supersymmetry will be ruled out by experiments, it's not the end.

I don't see why you are panicking about it so much. Yes, currently HP is a difficulty in particle physics. It's not the first one, and likely won't be the last.

 

[cube137]

Correct.
Wikipedia has a good article explaining it in some details: https://en.wikipedia.org/wiki/Hierarchy_problem

The thing is, not only supersymmetry can be a solution. Other solutions are already proposed (see wiki), and even more can be discovered in the future. If supersymmetry will be ruled out by experiments, it's not the end.

I don't see why you are panicking about it so much. Yes, currently HP is a difficulty in particle physics. It's not the first one, and likely won't be the last.

Real theoretical physicists are the ones panicking.. this is because if the Japan International Linear Collider and China Great Collider won't be built.. due to difficulty to persuade them to spent another $10 billion just to study the Higgs and top quark (remember C.N. Yang was discouraging China to build the Great Collider due to the non-appearance of Supersymmetry).. then there will no longer be any high-energy experimental guidance to the right final theory. And this would mark the end of physics.. and this is the nightmare scenario.. true for all theoretical physicists. I heard many of them are already changing fields to say banking, information or condense physics (away from theoretical physics).

 

[atyy]

Suppose there is no low-energy supersymmetry, at least not observable by any collider built in the next 500 years.

At low energies, there is still the search for dark matter.

At high energies, there is still the problem of quantum gravity.

At all energies, there is still the measurement problem of quantum mechanics.

So I'm sure there is lots of exciting fundamental physics to be done.

 

[cube137]

Suppose there is no low-energy supersymmetry, at least not observable by any collider built in the next 500 years.

At low energies, there is still the search for dark matter.

At high energies, there is still the problem of quantum gravity.

At all energies, there is still the measurement problem of quantum mechanics.

So I'm sure there is lots of exciting fundamental physics to be done.

https://profmattstrassler.com/artic...ics-basics/the-hierarchy-problem/naturalness/

In Figure 5 above. Can Bohmian quantum potential contribute anything to the so called "Contributions from quantum fluctuations of different fields"? Or is bohmian quantum potential excluded and why is that?

About the Hierarchy problem.
https://profmattstrassler.com/articles-and-posts/particle-physics-basics/the-hierarchy-problem/
quoting "This is the hierarchy problem.
Many theoretical physicists have devoted significant fractions of their careers to trying to solve this problem"

My main interest is also the Hierarchy Problem. In Wikipedia entry of it. It omits to mention "Scale Symmetry" in the Solutions part. If you know what it is. Please add the entry in Wiki. Also kindly share some thoughts in the thread that no one answered (no one knows what it is or don't care)?

https://www.physicsforums.com/threads/what-you-think-of-scale-symmetry.883237/
Thank you.

 

[nikkkom]

My main interest is also the Hierarchy Problem. In Wikipedia entry of it. It omits to mention "Scale Symmetry" in the Solutions part. If you know what it is.

It does not omit it. "Conformal solution".

 

[cube137]

Some of you may think that the Hierarchy Problem is all about why is the weak scale and Planck scale so far apart or has big difference in energies. And some like Nikkkom may state nature is just like that and there is no problem. But the problem is not that. The consequence of a large Planck mass is the quantum contribution to the Higgs mass would also reach Planck mass.. why it didn't happen is the main motivation of supersymmetry and even the LHC revolves around this Hierarchy Problem. The following gives good intro about it. https://profmattstrassler.com/articles-and-posts/particle-physics-basics/the-hierarchy-problem/ Nikkkom.. if you really understand the Hierarchy Problem.. please explain how you understand it and why you think all physicists are overreacting.

For others. Without Supersymmetry, Extra Dimensions, Multiverse, Scale Symmetry.. what papers or publications have you come across that is likely alternative to the solution to most perplexing puzzle beyond the standard model... the Hierarchy Problem?

In the above. I made a mistake in mentioning Nikkkom. It's ohwilleke I was attributing it to. In the thread https://www.physicsforums.com/threads/world-made-up-of-2nd-3rd-generation-particles.883560/page-3 he said (in message #51):

"The point is that the hierarchy problem is not a "problem" in the ordinary sense of the word and therefore doesn't call for an answer.

The physical constants of Nature have various values that are a fact of life. And, as long at those particular values that really exist in Nature are internally consistent with each other (for example, leading to the sum of all possible results of each possible situation adding up to 100% in each case and not leading to contradictory answers, in which case we probably screwed up measuring something), physical constants just "are", and it is basically a category error to ask "why" they are that value and not another when they are axioms and not theorized conclusions that flow from some other axioms."

ohwilleke thought the Hierarchy problem was just about why the weak scale and gravity scale differs so much. That's why he said it's fact of life. He seemed not to be aware that it's all about the quantum contributions raising the Higgs mass or field to Planck mass as detailed in https://profmattstrassler.com/articles-and-posts/particle-physics-basics/the-hierarchy-problem/
ohwilleke, read this part about "But while trying to figure out a possible explanation, physicists in the 1970s realized there was actually a serious problem, even a paradox, behind this number. The issue, now called the hierarchy problem, has to do with the size of the non-zero Higgs field, which in turn determines the mass of the W and Z particles."

 

[ChrisVer]

You are mixing several things when you talk for a nightmare scenario.
First of all, the LHC has not ruled out much yet, since its luminosity is still very low... Increasing luminosities will give us a better sensitivity to weak BSM signals.

He seemed not to be aware that it's all about the quantum contributions raising the Higgs mass or field to Planck mass

Under some assumptions (I think)...

$10 billion just to study the Higgs and top quark

Do you really believe that LHC got is fundings in order to search for SUSY and Dark Matter? The people/governments that "give" the money don't really care about these... also LHC did not only discover the Higgs. As if Government X that pays for CERN operations got anything amazing back from the Higgs' discovery...
The construction and operation of a collider produces several other things that are widely used worldwide (technological advancements and skills). I don't think you'd get any official to give you any large amount money for the probable discovery of an hypothetical particle- they are not physicists and so they are way more likely not to care or be fascinated by any discovery...

 

[nikkkom]

Well, in fact every science project, be it a new telescope, particle accelerator, spacecraft or something else, does need to justify to funding agencies why it should get the money. There are always competing projects.

"Give us $10bn for a new collider (telescope, planetary probe, ...), but we don't expect to find anything substantially new" isn't a good proposal.

 

[Vanadium 50]

Real theoretical physicists are the ones panicking..

Hogwash. And before you tell me that anyone who isn't panicking isn't a real theoretical physicist, let me tell you that no true Scotsman puts sugar on his porridge.

 

[cube137]

It does not omit it. "Conformal solution".

I've been stuck in this forum for one month because no one talks to me about Scale Symmetry which I have posted before https://www.physicsforums.com/threads/what-you-think-of-scale-symmetry.883237/
In the website https://www.wired.com/2014/08/multiverse/ it is mentioned if you click the scale symmetry button in the middle:

"A new idea holds that particles attain their masses as a result of scale-symmetry breaking: The underlying theory of nature lacks any concept of mass, and independent quantum effects cause mass to arise at two widely separated scales."

Can you explain Scale Symmetry in your own words especially how it is related to the Higgs field? How can mass arise at two widely separated scales? Can you elaborate?

 

[Haborix]

I think it is fairly easy to say that the majority of theoretical physicists don't actually care about this. Hell, they don't even work in this field!

 

[cube137]

I think it is fairly easy to say that the majority of theoretical physicists don't actually care about this. Hell, they don't even work in this field!

It only concerns the foundational theoretical physicists and things they say are not colorful or any optimism . Many of you may already have heard of the popular ones like Woit and Sabine. But maybe not so much on others. For example. In http://www.scientificamerican.com/article/supersymmetry-fails-test-forcing-physics-seek-new-idea/

"If nothing new turns up — an outcome casually referred to as the “nightmare scenario” — physicists will be left with the same holes that riddled their picture of the universe three decades ago, before supersymmetry neatly plugged them. And, without an even higher-energy collider to test alternative ideas, Falkowski says, the field will undergo a slow decay: “The number of jobs in particle physics will steadily decrease, and particle physicists will die out naturally.”"
..earlier it..
"Younger particle physicists now face a tough choice: follow the decades-long trail their mentors blazed, adopting ever more contrived versions of supersymmetry, or strike out on their own, without guidance from any intriguing new data.
It's a difficult question that most of us are trying not to answer yet," said Adam Falkowski, a theoretical particle physicist from the University of Paris-South in Orsay, France, who is currently working at CERN. In a blog post about the recent experimental results, Falkowski joked that it was time to start applying for jobs in neuroscience."

Anyway how many theoretical physicists are there in the world and how many are working on the foundational? Just estimate.

 

[Vanadium 50]

It only concerns the foundational theoretical physicists

Aye! No true Scotsman puts sugar on his porridge!

And it is far from all "foundational theoretical physicists" who hole the opinion you are ascribing to them. In short, this thread is built upon a statement that simply is not true.

 

[cube137]

Aye! No true Scotsman puts sugar on his porridge!

And it is far from all "foundational theoretical physicists" who hole the opinion you are ascribing to them. In short, this thread is built upon a statement that simply is not true.

Ok. Let me correct it then.. only a few percentage of foundational theoretical physicists are affected? How many percentage? A few months ago I didn't notice its but when I watched BBC Inside CERN 2016 about the null results of the diphoton bump and seen the faces of the Supersymmetry physicists who were sad. It made an impression of me. And when I read Sabine Hossenfelder and Peter Woit comment on it. It solidified on all. So I guess things are still rosy for others. Good to know. I'm only interested in the truth. Now nikkkom please share in your own words about Scale Symmetry and I'm done with it. Btw.. here's the words of Woit and Sabine (to prove I didn't make it all up):

Woit's:
https://www.edge.org/response-detail/23680
"These worries are in some sense just those of a narrow group of scientists, but I think they may have much wider implications. After centuries of great progress, moving towards ever deeper understanding of the universe we live in, we may be entering a new kind of era. Will intellectual progress become just a memory, with an important aspect of human civilization increasingly characterized by an unfamiliar and disturbing stasis? This unfortunately seems to becoming something worth worrying about."

Sabine's:
http://www.forbes.com/sites/startsw...discovers-no-more-new-particles/#493d55a43d6f
"If the bump goes away, this would catapult us into what has become known as the “nightmare scenario” for the LHC: The Higgs and nothing else. Many particle physicists are afraid of this scenario because, if it comes true, it will leave them without guidance, lost in a thicket of rapidly multiplying models that threaten to block out sunlight. Without some new physics, everyone is concerned we’ll have nothing to work with that we haven’t had already for 50 years. Without any new inputs that can tell us which direction to look towards in the ultimate goal of unification and/or quantum gravity, we’d finally have to admit the truth: we’re completely lost."

Sabine Hossenfelder is a theoretical physicist specialized in quantum gravity and high energy physics. So most don't hold her views? I'd better read the more optimistic ones where things are really rosy.

 

[tzimie]

And this would mark the end of physics.. and this is the nightmare scenario.. true for all theoretical physicists. I heard many of them are already changing fields to say banking, information or condense physics (away from theoretical physics).

Looks like they are already flooded the banking:
http://edesknews.com/canadian-economists-have-calculated-the-date-of-the-death-of-humanity/

If the investor believes in the multiverse, he may be more predisposed to the bets that can bring a big payoff with very low probability, and thus harder to avoid a very small risk of large losses, says Berezin. The fact that the choice of investment person, may consider that even if he does not earn her much money, it will comfort the idea that this will be one of his “doubles” in a distant galaxy or a different quantum state.

Therefore, if we assume that there are billions of parallel universes, where billions “versions” of each person, for investors, is preferable to more risky assets (such as stocks) is less risky (bonds), concludes the economist BCA Research.

 

[nikkkom]

I've been stuck in this forum for one month because no one talks to me about Scale Symmetry which I have posted before https://www.physicsforums.com/threads/what-you-think-of-scale-symmetry.883237/
In the website https://www.wired.com/2014/08/multiverse/ it is mentioned if you click the scale symmetry button in the middle:

"A new idea holds that particles attain their masses as a result of scale-symmetry breaking: The underlying theory of nature lacks any concept of mass, and independent quantum effects cause mass to arise at two widely separated scales."

Can you explain Scale Symmetry in your own words especially how it is related to the Higgs field? How can mass arise at two widely separated scales? Can you elaborate?

There is a thread for this already:

https://www.physicsforums.com/threads/top-higgs-higgs-vev-relation-from-conformal-symmetry.768598/

 

[ChrisVer]

the OPINION of a few physicists is not creating physics... especially when it's outside their reach... as for the faces of people or whatever, that is totally lame- all the bets were against the diphoton bump so nobody had much belief in it...
Now there were some people who trusted it would be something good and put way too much hope on it... when people lose their reason of hope they can get sad and nihilists... That's what comes out of Sabine... I won't even comment on Wolt's words, since they are meaningless...

 

[cube137]

There is a thread for this already:

https://www.physicsforums.com/threads/top-higgs-higgs-vev-relation-from-conformal-symmetry.768598/

Thanks. It's very interesting.. I've been looking for the relationship of the Hierarchy Problem, electron self energy and cosmological problem.. it can solve them all at once. I googled "Conformal Invariance" and read many papers.. but can't understand them totally. In the paper referenced in your link for example. It described:

"All these puzzling facts seem to imply that the parameters of the Standard Model are not at all accidental.
Instead, they may be fully determined by an assumption, that the Standard Model is a low energy limit of a
very special fundamental theory defined naturally at the Planck scale, which is the next fundamental threshold
in particle physics. Moreover, these relations imply that there is some additional symmetry, which underlies the
Standard Model and the deeper fundamental theory. This symmetry should automatically protect the vacuum
expectation value of the Higgs field (in order to protect relations like (5)) and, hence, solve the hierarchy problem
(in the spirit of [11, 12])."

Can you share what is this special fundamental theory defined naturally at the Planck scale is? Goggling the entire net. There is no layman article about Conformal Symmetry. With the hundreds and tons of laymen references about Supersymmetry. It's time we make layman references or versions about Conformal Symmetry. Maybe one of you could write an article at the Discover Magazine or Sci-Am.. or if no one would do it. I will. It's quite interesting. With the almost possible demise of Supersymmetry. It's time to replace the popular books and layman articles with Conformal Symmetry and let it spread far and wide.

 

[cube137]

Thanks. It's very interesting.. I've been looking for the relationship of the Hierarchy Problem, electron self energy and cosmological problem.. it can solve them all at once. I googled "Conformal Invariance" and read many papers.. but can't understand them totally. In the paper referenced in your link for example. It described:

"All these puzzling facts seem to imply that the parameters of the Standard Model are not at all accidental.
Instead, they may be fully determined by an assumption, that the Standard Model is a low energy limit of a
very special fundamental theory defined naturally at the Planck scale, which is the next fundamental threshold
in particle physics. Moreover, these relations imply that there is some additional symmetry, which underlies the
Standard Model and the deeper fundamental theory. This symmetry should automatically protect the vacuum
expectation value of the Higgs field (in order to protect relations like (5)) and, hence, solve the hierarchy problem
(in the spirit of [11, 12])."

Can you share what is this special fundamental theory defined naturally at the Planck scale is? Goggling the entire net. There is no layman article about Conformal Symmetry. With the hundreds and tons of laymen references about Supersymmetry. It's time we make layman references or versions about Conformal Symmetry. Maybe one of you could write an article at the Discover Magazine or Sci-Am.. or if no one would do it. I will. It's quite interesting. With the almost possible demise of Supersymmetry. It's time to replace the popular books and layman articles with Conformal Symmetry and let it spread far and wide.

To elaborate. Although I spent so much time reading more than 10 papers about Conformal Symmetry or Scale Symmetry. They didn't define it first but talk about it directly so even though I read many of them. I can't understand the core of it. What really is Conformal Symmetry. Please choose one of the following possible explanations (based on how I understand it).

a. Is it akin to superstrings where the dynamics of the Planck scale can define the lower energy sector.. so superstrings is automatically a Conformal Symmetry because of it?

b. Is the papers a search for other alternative to superstings?

c. or does Conformal Symmetry mean what goes on in the lower sector has duplicate in the plance scale. meaning we have our own versions in the plank scale?

d. none of the above? What is it then?

When I read those 10 papers. I switch between the above in guessing what they are trying to say.

Conformal Symmetry may become the most important concept to solve the Hieararchy Problem.. it's now the only theory left.. Supersymmetry is just awaiting its burial.. Extra dimensions are not seen, Multiverse is excess baggage. Fine tuning is unlikely (if this is true.. it simply means we are living in simulations in the Tegmark Mathematical Universe)...

Also I hope Conformal Symmetry can give us extra dynamics or degrees of freedom in the lower sector.. which version has it? For over 10 years. I've been studying (reading hundreds of books of) physics looking for the theory that can explain my world.. and hope Conformal Symmetry is close to it. I'm weary already and would hit 50 years old in a few years. I have so many other things to do but because theoretical physicists ignore other things by refusing to see outside the box.. I'm forced to spend every night studying physics instead of enjoying other activities.

 

[cube137]

After reading dozen more papers. I finally understand what's Conformal Symmetry is all about. nikkkom wiki sharing of the Conformal Solution is already good enough... if you can understand it. specifically it's about:

"Without supersymmetry, a solution to the hierarchy problem has been proposed using just the Standard Model. The idea can be traced back to the fact that the term in the Higgs field that produces the uncontrolled quadratic correction upon renormalization is the quadratic one. If the Higgs field had no mass term, then no hierarchy problem arises. But by missing a quadratic term in the Higgs field, one must find a way to recover the breaking of electroweak symmetry through a non-null vacuum expectation value. This can be obtained using the Weinberg–Coleman mechanism with terms in the Higgs potential arising from quantum corrections. Mass obtained in this way is far too small with respect to what is seen in accelerator facilities and so a conformal Standard Model needs more than one Higgs particle. This proposal has been put forward in 2006 by https://en.wikipedia.org/w/index.php?title=Krzysztof_Meissner&action=edit&redlink=1 and https://en.wikipedia.org/w/index.php?title=Hermann_Nicolai&action=edit&redlink=1 [4] and is currently under scrutiny. But if no further excitation is observed beyond the one seen so far at LHC, this model would have to be abandoned."

Isn't the Weinberg-Coleman mechanism a bit ad-hoc compared to the standard one? If it's false.. and you will notice in the wiki page all solutions are already *almost* excluded including it. So please share other solutions to the Hieararchy Problem if you encountered them. For those of us who plan to become physicists. I think we can still catch up 10 years from now isn't it. Would the condition remain as now especially if no new results in the LHC, LUX, Icecube and other upcoming detectors... Thanks.

 

[mitchell porter]

One classic approach that you haven't mentioned, is Composite Higgs. The large corrections to the mass are a problem specifically for scalar fields, but if the Higgs is, for example, a bound state of two fermions, then the Higgs doesn't even exist at the Planck scale.

 

[nikkkom]

To elaborate. Although I spent so much time reading more than 10 papers about Conformal Symmetry or Scale Symmetry. They didn't define it first but talk about it directly so even though I read many of them. I can't understand the core of it. What really is Conformal Symmetry.

Scale symmetric theory equations have a form which is unchanged if all spacetime dimensions are uniformly enlarged or shrank (IOW: objects change size, but not shape), combined with corresponding transformations of the other fields in the theory.

Conformally symmetric theory has scale symmetry plus another, somewhat more difficult to visualize special conformal transformation (see wiki), which also in some sense conserves shape.

 

[cube137]

Scale symmetric theory equations have a form which is unchanged if all spacetime dimensions are uniformly enlarged or shrank (IOW: objects change size, but not shape), combined with corresponding transformations of the other fields in the theory.

Conformally symmetric theory has scale symmetry plus another, somewhat more difficult to visualize special conformal transformation (see wiki), which also in some sense conserves shape.

When you watch movies.. the length and mass are not really fundamentally there in the screen but just patterns in the film. I wonder if scale symmetry and holographic principle is compatible. Our universe just "movies" of some film in a "event horizon" storage. Even if scale symmetry is true. what is further behind it.. maybe Tegmark Mathematical Universe is correct. Everything is just simulation and designed from the beginning. This would be a great solution to the Hierarchy Problem. Without Supersymmetry, Extra Dimensions or Multiverse.. Tegmark's Simulated Universe may be the theory of last resort.