5 Higgs-like bosons -- natural supersymmetry required?

[kodama]

MSSM and nMSSM require 5 higgs like bosons in addition to the 126 GEV the SM predicts.

thus far LHC has not found any of them.

what masses are predicted for Natural SUSY for these additional higgs and how much of a problem is it that the LHC has not found them?

if natural SUSY is correct should additional higgs have been found in LHC run 2?

 

[mathman]

Maybe. However, the masses of the additional Higgs bosons are guesswork right now.

 

[Vanadium 50]

MSSM and nMSSM require 5 higgs like bosons in addition to the 126 GEV the SM predicts.

No, it predicts five in total.

 

[kodama]

No, it predicts five in total.

given 1 higgs has a mass of 126 gev, what are the range of values for the other 4 predicted higgs masses?

 

[ohwilleke]

What the LHC has done has created mass exclusion ranges for various prospective extra Higgs bosons. Specifically, a positively charged Higgs boson (H+), a negatively charged Higgs boson (H-), a pseudo-scalar Higgs boson (A) and an extra scalar Higgs boson (either H or h depending on whether the one at 126 GeV is the heavier one or the lighter one).

There are really no predictions regarding the other Higgs masses. They are free parameters in the model. All we have are experimental exclusions.

Exclusions as of 2013 can be found at https://cds.cern.ch/record/1556867/files/ATL-PHYS-SLIDE-2013-391.pdf

To summarize, as of that time, a heavy Higgs was excluded from 145 GeV to 710 GeV; A was excluded up to masses of about 200 GeV, charged Higgs were excluded up to 160 GeV. Almost all of those limits have grown larger over time.

One way for an extra Higgs to hide is for it to be degenerate with the 126 GeV Higgs in mass. But, the observed Higgs is so purely scalar than there can't be a degenerate mass A.

A 2015 summary is here: https://cds.cern.ch/record/2117949/files/ATL-PHYS-PROC-2015-206.pdf but has no "quotable" limits.

The particle data group summarizes limits for neutral extra Higgs here: http://pdglive.lbl.gov/Particle.action?node=S055 (it is quite conservative due to the model dependency of the limits since the couplings of extra Higgs bosons are uncertain, if they exist).

The particle data group limits for charged Higgs bosons are here: http://pdglive.lbl.gov/Particle.action?node=S064 and are also far too conservative.

A preprint search for 2HDM (two Higgs doublet models) in the experiment subsection would probably reveal more up to date papers with more rigorous limits than PDG does.

 

[fanieh]

What the LHC has done has created mass exclusion ranges for various prospective extra Higgs bosons. Specifically, a positively charged Higgs boson (H+), a negatively charged Higgs boson (H-), a pseudo-scalar Higgs boson (A) and an extra scalar Higgs boson (either H or h depending on whether the one at 126 GeV is the heavier one or the lighter one).

There are really no predictions regarding the other Higgs masses. They are free parameters in the model. All we have are experimental exclusions.

Exclusions as of 2013 can be found at https://cds.cern.ch/record/1556867/files/ATL-PHYS-SLIDE-2013-391.pdf

To summarize, as of that time, a heavy Higgs was excluded from 145 GeV to 710 GeV; A was excluded up to masses of about 200 GeV, charged Higgs were excluded up to 160 GeV. Almost all of those limits have grown larger over time.

One way for an extra Higgs to hide is for it to be degenerate with the 126 GeV Higgs in mass. But, the observed Higgs is so purely scalar than there can't be a degenerate mass A.

A 2015 summary is here: https://cds.cern.ch/record/2117949/files/ATL-PHYS-PROC-2015-206.pdf but has no "quotable" limits.

The particle data group summarizes limits for neutral extra Higgs here: http://pdglive.lbl.gov/Particle.action?node=S055 (it is quite conservative due to the model dependency of the limits since the couplings of extra Higgs bosons are uncertain, if they exist).

The particle data group limits for charged Higgs bosons are here: http://pdglive.lbl.gov/Particle.action?node=S064 and are also far too conservative.

A preprint search for 2HDM (two Higgs doublet models) in the experiment subsection would probably reveal more up to date papers with more rigorous limits than PDG does.

dear olwilleke, what kind of LHC experimental setups can prove that the Glashow-Weinberg-Salam Higgs as modeled by Higgs, Kibble, Guralnik, Hagen, Brout and Englert is correct? I read that the mass terms in the Higgs can come from other ways like the Coleman-Weinberg mechanism, etc.. If the latter is proven. Do they withdraw the Nobel Prize of Peter Higgs?

 

[ohwilleke]

What the LHC can do is prove that the observed particle has all of the properties of the Standard Model Higgs boson. It has done a very good job in a very short time of doing just that. It has shown that it has the right quantum numbers to a very high precision. It has shown that the couplings that have been documented are the predicted ones to within a very modest margin of error. It is in the process of demonstrating that it is produced in all of the predicted ways. The width of the Higgs boson resonance has been constrained to a far smaller range of values than had been expected to be possible at this point due to some clever techniques.

Even if one or another detail of the properties of the Higgs boson turn out to be not exactly as predicted, Peter Higgs absolutely deserves his Nobel Prize for coming up with an idea so close to the mark forty years in advance. Nobody faults Newton for not discovering General Relativity when none of the evidence available at the time would have made it possible for him to do so. Nobody faults Maxwell for not discovering quantum electrodynamics. A scientist's job is to move our understanding forward so that the next generation can stand on the shoulders of giants. Peter Higgs meets that very high bar.

 

[kodama]

What the LHC can do is prove that the observed particle has all of the properties of the Standard Model Higgs boson. It has done a very good job in a very short time of doing just that. It has shown that it has the right quantum numbers to a very high precision. It has shown that the couplings that have been documented are the predicted ones to within a very modest margin of error. It is in the process of demonstrating that it is produced in all of the predicted ways. The width of the Higgs boson resonance has been constrained to a far smaller range of values than had been expected to be possible at this point due to some clever techniques.

Even if one or another detail of the properties of the Higgs boson turn out to be not exactly as predicted, Peter Higgs absolutely deserves his Nobel Prize for coming up with an idea so close to the mark forty years in advance. Nobody faults Newton for not discovering General Relativity when none of the evidence available at the time would have made it possible for him to do so. Nobody faults Maxwell for not discovering quantum electrodynamics. A scientist's job is to move our understanding forward so that the next generation can stand on the shoulders of giants. Peter Higgs meets that very high bar.

what would be a reason then to build a $10 billion higgs factory one proposed in Japan, an ep collider, if the LHC can do that.

for $10 billion why not build a more powerful 100 GEV+ 50-100km hadron collider?

 

[kodama]

What the LHC has done has created mass exclusion ranges for various prospective extra Higgs bosons. Specifically, a positively charged Higgs boson (H+), a negatively charged Higgs boson (H-), a pseudo-scalar Higgs boson (A) and an extra scalar Higgs boson (either H or h depending on whether the one at 126 GeV is the heavier one or the lighter one).

There are really no predictions regarding the other Higgs masses. They are free parameters in the model. All we have are experimental exclusions.

Exclusions as of 2013 can be found at https://cds.cern.ch/record/1556867/files/ATL-PHYS-SLIDE-2013-391.pdf

To summarize, as of that time, a heavy Higgs was excluded from 145 GeV to 710 GeV; A was excluded up to masses of about 200 GeV, charged Higgs were excluded up to 160 GeV. Almost all of those limits have grown larger over time.

One way for an extra Higgs to hide is for it to be degenerate with the 126 GeV Higgs in mass. But, the observed Higgs is so purely scalar than there can't be a degenerate mass A.

A 2015 summary is here: https://cds.cern.ch/record/2117949/files/ATL-PHYS-PROC-2015-206.pdf but has no "quotable" limits.

The particle data group summarizes limits for neutral extra Higgs here: http://pdglive.lbl.gov/Particle.action?node=S055 (it is quite conservative due to the model dependency of the limits since the couplings of extra Higgs bosons are uncertain, if they exist).

The particle data group limits for charged Higgs bosons are here: http://pdglive.lbl.gov/Particle.action?node=S064 and are also far too conservative.

A preprint search for 2HDM (two Higgs doublet models) in the experiment subsection would probably reveal more up to date papers with more rigorous limits than PDG does.

do these other Higgs suffer from same higgs hiearchy problem that the SM 126 gev higgs does?

wouldn't multiple higgs interact both with one another and with SM particles + SUSY partners?

 

[ohwilleke]

For my druthers, $10 billion would be better spent on space telescopes (including gravitational wave detectors) than on a new collider of any kind.

 

[kodama]

For my druthers, $10 billion would be better spent on space telescopes (including gravitational wave detectors) than on a new collider of any kind.

maybe there are SUSY partners just beyond LHC energies but within 100 TEV collider range. verifying SUSY might be more important to particle physics than space telescopes

 

[ohwilleke]

do these other Higgs suffer from same higgs hiearchy problem that the SM 126 gev higgs does?

wouldn't multiple higgs interact both with one another and with SM particles + SUSY partners?

Nobody knows because nobody has ever seen any evidence that they exist and there are several varied hypotheses regarding their properties (unlike the SM Higgs whose properties were completely determined by its mass).

 

[kodama]

Nobody knows because nobody has ever seen any evidence that they exist and there are several varied hypotheses regarding their properties (unlike the SM Higgs whose properties were completely determined by its mass).

if natural SUSY and by extension MSSM and nMSSM were realized in nature, what can be said on these other higgs and their interactions with SM + SUSY on purely theoretical grounds

 

[ohwilleke]

maybe there are SUSY partners just beyond LHC energies but within 100 TEV collider range. verifying SUSY might be more important to particle physics than space telescopes

Even if SUSY did exist at those energy scales, it wouldn't be very useful and it is not like the laws of the universe are going anywhere. And, if SUSY exists anywhere, it is almost certainly not "just beyond LHC energies" because if it were, there would be a lot more anomalies in the LHC data because some observables are sensitive to much higher energy phenomena. We might not know just what was around the corner, but we would know that something was amiss. For SUSY to have no meaningful impact on LHC scale physics it has to be way over the mountains, across the desert and out across the sea, not just around the corner.

In contrast, we know for a fact that we are observing BSM physics with telescopes today that give rise to dark matter phenomena (dark energy is not really BSM since it can be fully explained through GR with the cosmological constant). And, we have myriad ways that we can narrow the range of theories that can fit the data associated with this BSM physics simply by having better instrumentation. Why spend our money on science that might, just possibly maybe reveal new physics when we can spend it on physics that will definitely reveal BSM physics of some kind and the only question is what kind?

 

[ohwilleke]

if natural SUSY and by extension MSSM and nMSSM were realized in nature, what can be said on these other higgs and their interactions with SM + SUSY on purely theoretical grounds

Not much. Even natural SUSY, MSSM and nMSSM offer lots of wiggle room and choices, in addition to having way more free parameters than the already ugly SM.

 

[kodama]

Even if SUSY did exist at those energy scales, it wouldn't be very useful and it is not like the laws of the universe are going anywhere. And, if SUSY exists anywhere, it is almost certainly not "just beyond LHC energies" because if it were, there would be a lot more anomalies in the LHC data because some observables are sensitive to much higher energy phenomena. We might not know just what was around the corner, but we would know that something was amiss. For SUSY to have no meaningful impact on LHC scale physics it has to be way over the mountains, across the desert and out across the sea, not just around the corner.

In contrast, we know for a fact that we are observing BSM physics with telescopes today that give rise to dark matter phenomena (dark energy is not really BSM since it can be fully explained through GR with the cosmological constant). And, we have myriad ways that we can narrow the range of theories that can fit the data associated with this BSM physics simply by having better instrumentation. Why spend our money on science that might, just possibly maybe reveal new physics when we can spend it on physics that will definitely reveal BSM physics of some kind and the only question is what kind?

ed witten for one is a fan of building the chinese collider.

"
With a circumference of 50 to 100 km, however, the proposed Chinese accelerator Circular Electron Positron Collider (CEPC) will generate millions of Higgs boson particles, allowing a more precise understanding.

"The technical route we chose is different from LHC. While LHC smashes together protons, it generates Higgs particles together with many other particles," Wang said. "The proposed CEPC, however, collides electrons and positrons to create an extremely clean environment that only produces Higgs particles," he added.

The Higgs boson factory is only the first step of the ambitious plan. A second-phase project named SPPC (Super Proton-Proton Collider) is also included in the design－a fully upgraded version of LHC.

LHC shut down for upgrading in early 2013 and restarted in June with an almost doubled energy level of 13 TeV, a measurement of electron volts.

"LHC is hitting its limits of energy level, it seems not possible to escalate the energy dramatically at the existing facility," Wang said. The proposed SPPC will be a 100 TeV proton-proton collider.


If everything moves forward as proposed, the construction of the first phase project CEPC will start between 2020 and 2025, followed by the second phase in 2040.

"China brings to this entire discussion a certain level of newness. They are going to need help, but they have financial muscle and they have ambition," said Nima Arkani Hamed from the Institute for Advanced Study in the United States, who joined the force to promote CEPC in the world.

David J. Gross, a US particle physicist and 2004 Nobel Prize winner, wrote in a commentary co-signed by US theoretical physicist Edward Witten that although the cost of the project would be great, the benefits would also be great. "China would leap to a leadership position in an important frontier area of basic science," he wrote.

http://www.dailygalaxy.com/my_weblo...universe-so-far-the-standard-model-seems.html

Nima Arkani Hamed Ed Witten and David Gross thinks China should build a 100 TEV scale collider presumably with Chinese money

perhaps the US and Russia and EU can build telescopes ;)-)

perhaps a 100 TEV collider is needed to create dark matter and explore other BSM physics.

2040 is a long time from now :'(

 

[kodama]

Not much. Even natural SUSY, MSSM and nMSSM offer lots of wiggle room and choices, in addition to having way more free parameters than the already ugly SM.

SUSY is invoked to explain the higgs fine-tuning, but all those free parameters MSSM nmmsm has seems to also be fine tuning so as to avoid conflict with experiment.

 

[ohwilleke]

Absolutely.

 

[kodama]

Absolutely.

the SM has a fine tuning problem with the higgs stability and theta in QCD. if there is an axion, that would explain why QCD theta is zero, which leaves 1 fine tuning problem, the higgs.

SUSY MSSM and nMSSM, no SUSY has been seen by tevatron, ep colliders, ilc, LHC colliders. no SUSY seen in neutron, electron EDM or rare decays. no gluinos and squarks produced in proton colliders. LHC sees no SUSY no rare decay rates deviate from SM values.
no SUSY dark matter observed.

so SUSY MSSM and nMSSM has 120 parameters, and each has to be fine tuned to avoid the above constraints.

so in effect the SUSY hypothesis may solve 1 fine tuning in the higgs sector, by introducing 5 higgs, and 120 parameters that need to be fine tuned to avoid conflict with experiment plus another set of particles "hidden sector" involved in SUSY-breaking, which might have additional fine tuning issues. occam's razor would suggest that SM is more parsimonious than SUSY.

and the LHC has seen no evidence of natural SUSY that would explain higgs stability

 

[ohwilleke]

"Fine tuning" is not a problem, it is a category error that looks like a problem only in the minds in misguided theoretical physicists. More humble physicists recognize that the laws of nature and its physical constants are what they are and are not subject to adjustment. The amount of sheer brainpower and time and money that has been spent thinking otherwise is a travesty.

 

[kodama]

"Fine tuning" is not a problem, it is a category error that looks like a problem only in the minds in misguided theoretical physicists. More humble physicists recognize that the laws of nature and its physical constants are what they are and are not subject to adjustment. The amount of sheer brainpower and time and money that has been spent thinking otherwise is a travesty.

so what's your fav solution to the higgs hiearchy ? apparently susy isn't the correct answer according to the LHC

 

[ohwilleke]

My position is that the Higgs hierarchy isn't a problem that calls for a solution.

If Nature wants to make heaps of huge numbers almost exactly balance out, but not quite, that is Nature's right and it isn't for us to second guess.

The Higgs mass has the values we have measured it to have. It comes to these values because all of the other physical constants and equations of the SM are just right to produce this result. Asking for a solution to the higgs hierarchy is like asking for a solution to "the problem" of why I was born on a Tuesday. There may be a reason for that, but the fact that I was born on a Tuesday is immutable and is not a problem. First and foremost, that is just how the world happens to be.

Even if there is a deeper reason that a constant has a particular value, that never means that the value that we observe is a "problem". Perhaps a mystery, but not a problem.

At most the question ought to be open ended along the lines of, "is there any deeper reason that the Standard Model have the physical constants that it has, and if so which experimentally measured constants of the model can be derived from other constants, and if they can be derived from other constants, how is this done"? (A more thoughtful version of the same question would touch on the concept of degrees of freedom in some way because, for example, it might be the case than any two of three constants in the SM is sufficient to perfectly predict the third.)

Moreover, an answer to that more general question should not start with any presuppositions about what values those physical constants "should have" at least so long as we don't have any serious internal inconsistency between constants in the model that is not attributable to measurement or calculation errors.

Yes, I have some hunches about why some Standard Model constants have the values that they do, some of which simple involve the existence of numerical relationships that I think are probably not coincidences even though I don't know any deeper reasons for, and some of which amount to an ansatz or conjecture. Nobody needs to hear my pet theories on those topics in this thread. Certainly, like most people who have thought seriously about the question, I don't actually think that all 26+ experimentally measured Standard Model constants are all purely arbitrary (counting exactly how many comes down to definitional issues and some can be traded for others so the list wouldn't be identical for everyone, also, for example, should Plank's constant be considered a Standard Model experimentally measured physical constant? what about the speed of light? You can't do SM calculations without either and they aren't mathematical abstractions either).

But, I also don't think that the Higgs boson mass, or the zero value of the theta term in QCD present any different kind of question than the fundamental particle masses or the coupling constants or the CKM and PMNS matrix parameters. The fact that someone has a counterfactual theory about the value that a constant should have had doesn't make the physical constant that someone has a theory about any more of a problem than one that there is no accepted theory to explain.

 

[kodama]

the issue with the higgs is also that the higgs is sensitive to the cutoff of the theory where new physics arise, and that quantum processes would drive up the mass of the higgs to Planck level values.

 

[ohwilleke]

the issue with the higgs is also that the higgs is sensitive to the cutoff of the theory where new physics arise, and that quantum processes would drive up the mass of the higgs to Planck level values.

Clearly, that mass of the Higgs has not been driven up to Planck level values. So, either there are no physics, or the theory that predicts that this will happen is wrong. My money would be on the former, although both might be true.

 

[kodama]

Clearly, that mass of the Higgs has not been driven up to Planck level values. So, either there are no physics, or the theory that predicts that this will happen is wrong. My money would be on the former, although both might be true.

option 1
new physics appears to be required for baryogenesis dark matter, inflation etc.

option 2
since it seems standard QFT and SM physics makes this "prediction", it would seem standard QFT and SM physics is "wrong"

 

[kodama]

For my druthers, $10 billion would be better spent on space telescopes (including gravitational wave detectors) than on a new collider of any kind.

off topic

one reason chinese are interested in building a $10 billion 100km circumference 100tev-scale hadron collider is they think all the scientific and technical know-how in building a collider that scale will greatly stimulate technological advancements and training engineers in china specifically.

how would that benefit compare with building $10 billion telescopes?

nasa already has several such telescopes planned including james webb telescope 2018 price tag $8 billion

of course there's no guarantee that chinese communist party will still be in power by 2040

 

[ohwilleke]

option 1
new physics appears to be required for baryogenesis dark matter, inflation etc.

option 2
since it seems standard QFT and SM physics makes this "prediction", it would seem standard QFT and SM physics is "wrong"

Keep in mind that when I said "the theory that predicts that this will happen is wrong" is responding to your statement that "the higgs is sensitive to the cutoff of the theory where new physics arise[.]" So the exclusion of "new physics" is limited to new physics of the kind that could have any impact on the Higgs boson mass.

Nothing in the Standard Model predicts that any of the kinds of new physics that we know simply must be out there has to have anything to do with Higgs physics.

It is not at all obvious that baryogenesis or inflation would have any connection to the Higgs boson mass (there are theories where it does, but far more where it does not). Similarly, if new physics arise from quantum gravity or some subtle modification of general relativity, there is no reason it would have any measurable impact on Higgs physics or Standard Model physics more generally.

It is likewise perfectly possible that dark matter particles may be in a sector of physics that has nothing to do with the Higgs boson. Indeed, if a dark matter particle were close to the mass of the bottom quark (about 4.2 GeV) or more, and less than half of the Higgs boson mass (about 62.5 GeV) this would be the dominant type of particle to which Higgs bosons decayed or at least a very high frequency subdominant decay mode, either of which would produce extremely noticeable missing energy signatures where Higgs boson decays would be expected, and the total frequency with which Higgs bosons are produced would seem to be far below what was predicted by the Standard Model.

Lighter dark matter particles that interacted with the Higgs boson could have been missed so far (for example, we have not yet observed Higgs boson decays to charm quarks which are the third most common form of fermion pair decays predicted for the SM Higgs boson, due to their lower frequency and the larger backgrounds involved than in bottom quark pair and tau lepton pair decays which have been observed). But, Higgs physics should, in theory, be more sensitive to higher energy new physics than to lower energy new physics.

 

[fanieh]

My position is that the Higgs hierarchy isn't a problem that calls for a solution.

If Nature wants to make heaps of huge numbers almost exactly balance out, but not quite, that is Nature's right and it isn't for us to second guess.

dear ohwilleke, so you are more into fine tuning than Susy or others? but more physicists dislike fine tuning

 

[haushofer]

Isn''t the cancellation of big numbers in the renormalisation of the higgsmass an artefact of doing perturbation theory? And if we could develop math.techniques to calculate amplitudes exactly, the problem wouldn't be there?

 

[ohwilleke]

dear ohwilleke, so you are more into fine tuning than Susy or others? but more physicists dislike fine tuning

I'm saying "fine tuning" is a meaningless concept.

 

[fanieh]

I'm saying "fine tuning" is a meaningless concept.

You stated "If Nature wants to make heaps of huge numbers almost exactly balance out, but not quite, that is Nature's right and it isn't for us to second guess.". Are you more into multiverse or programmed universe? or are you into Susy? You can't be neither of them. Some physicists spend a lifetime solving for the "Hierarchy Problem" or "Hierarchy Puzzle". You can't just slid it under the rug.. if you are not Susy.. then you believe either in multiverse or programmed universe or others. What are you? Don't argue using philosophy but physics. What you are arguing is akin to saying so what if there is human body. It is nature's right and it isn't for us to second guess.. then genetics and evolution would be thrown out of the window.

 

[ohwilleke]

You absolutely don't have to be into multiverse or programmed universe or SUSY.

The fact that some physicists spend their lifetimes wondering why the physical constants aren't different from what they are in real life is an unfortunate waste of brain power. It is a lost generation of an entire sub-discipline really. A tragedy of epic proportions that has set the discipline back because it got lazy about the scientific method. The same can be said for the multiverse people and the anthropic principle folks. It isn't just the Hierarchy Problem/Puzzle. It is the strong CP problem as well. It is the "fine tuning" problem. So are all variations of the question of whether something in physics is "natural." All of those misguided research agendas are devoted to solving problems that aren't really problems.

Understanding how the world works given the rules of the game that exist is an entirely different venture from asking why the rules of the game that exist are not different from what they are because you have a model that says that they should be different. The notion that the world really runs according to your flawed model and then is corrected in some undiscovered way is dubious at best and always has been.

The problem is a philosophical one to its core. There is no physics answer to why the fundamental constants of nature have the values that they do if you go deep enough, because at some point the question itself is nonsensical. We might, if we are lucky, determine that the 30 or so fundamental constants of physics can actually be reduced to some smaller number of fundamental constants N<30 because some of those constants may be functionally related to other constants. But, at some point, when you have a given set of fundamental constants, those just are the laws of Nature and there is no "why?" to ask.

 

[kodama]

i agree what you say, the issue with the higgs though

in reviewing the Higgs, a physicists Flipip Tanedo says that the bare mass of higgs in presence of quantum corrections is like finding an ice cube not melted in the hot oven after several hours. some explanation is necessary.

One Higgs is the loneliest number
07/30/15
By Katie Elyce Jones
Physicists discovered one type of Higgs boson in 2012. Now they’re looking for more.

When physicists discovered the Higgs boson in 2012, they declared the Standard Model of particle physics complete; they had finally found the missing piece of the particle puzzle.

And yet, many questions remain about the basic components of the universe, including: Did we find the one and only type of Higgs boson? Or are there more?

A problem of mass
The Higgs mechanism gives mass to some fundamental particles, but not others. It interacts strongly with W and Z bosons, making them massive. But it does not interact with particles of light, leaving them massless.

These interactions don’t just affect the mass of other particles, they also affect the mass of the Higgs. The Higgs can briefly fluctuate into virtual pairs of the particles with which it interacts.

Scientists calculate the mass of the Higgs by multiplying a huge number—related to the maximum energy for which the Standard Model applies—with a number related to those fluctuations. The second number is determined by starting with the effects of fluctuations to force-carrying particles like the W and Z bosons, and subtracting the effects of fluctuations to matter particles like quarks.

While the second number cannot be zero because the Higgs must have some mass, almost anything it adds up to, even at very small numbers, makes the mass of the Higgs gigantic.

But it isn’t. It weighs about 125 billion electronvolts; it’s not even the heaviest fundamental particle.

“Having the Higgs boson at 125 GeV is like putting an ice cube into a hot oven and it not melting,” says Flip Tanedo, a theoretical physicist and postdoctoral researcher at the University of California, Irvine.

 

[ohwilleke]

The example given is a horrible one, because it poses the question as a question of probability. But, when it comes to the fundamental constants of nature, probability is not an appropriate way to frame the question.

"The Higgs mechanism gives mass to some fundamental particles, but not others. It interacts strongly with W and Z bosons, making them massive. But it does not interact with particles of light, leaving them massless."

This has a pretty obvious explanation. Fundamental particles that interact via the weak force have mass; fundamental particles that do not interact via the weak force do not. The Higgs field is deeply and fundamentally related to the weak force in electroweak unification, so this is no surprise.

Likewise, the question of whether there is one Higgs or more is an empirical one.

But, the fact that all of the constants of the SM interact in such a way that the Higgs mass arising from those interactions is exactly 125.___ GeV is a "so what?", not a problem. Because, there aren't a host of possible probable values for all of the SM constants only one set of which interacts just so. There is just one possible value for each of these constants and this happens to work.

I think that there are more useful ways to think about how the Higgs mass gets the value that it does than the conventional formulation in which it seems mysterious. For example, the sum of the square of the fundamental boson masses is almost exactly half of the square of the Higgs vev (which in turn is basically a function of the weak force coupling constant). Likewise, the sum of the square of the fundamental fermion masses is almost exactly the square of the Higgs vev, implying a balance between the fermions and the bosons.

In that frame of analysis, the Higgs mass has the mass it does in order to make the boson side of the contributions to the Higgs vev add up, and the top quark has the mass it does in order to make the fermion side of the contributions to the Higgs vev add up, and the Higgs vev has the value it does because of the magnitude of the weak force coupling constant. Not terribly mysterious.

More importantly, whether this particular example has a true and correct physical basis or not, the point is that if you are looking at the world from a perspective that makes the world look "unnatural", or "fine tuned" or like a "problem" you are probably looking at the universe from the wrong perspective and looking at the universe from another perspective will probably make it look like it makes sense (although there are absolute no guarantees of this. It's right in the user's manual. Life is not required to be fair or easy to understand, and neither is Nature. What, you mean they threw out your user's manual when you were born? Tough luck for you.)

Similarly, there is a heuristic argument for why the CP violation parameter theta of the strong force should be exactly zero, rather than of on the order of one, as "strong CP problem" advocates suggest. This is because CP violation calls for a broken time reversal symmetry. And, if you take the perspective of a massless gluon or massless photon, the carrier boson does not experience time, so it shouldn't know the difference between going forward in time and going backward in time. In contrast, the W boson which is massive, does experience time, so it knows the difference between going forward in time and going backward in time, and it therefore can implement a CP violation.

Again, the point is not that this heuristic answer really is the true and correct solution to the strong CP problem. Maybe it is, maybe it isn't. But, if you are looking at the problem from a perspective that makes the laws of nature look like a problem, or unnatural or finely tuned, then you are probably looking at the problem from the wrong perspective anyway, because the actual value of a physical constant is incapable of being a problem or being unnatural or being fine tuned. It simply is.

 

[fanieh]

You absolutely don't have to be into multiverse or programmed universe or SUSY.

The fact that some physicists spend their lifetimes wondering why the physical constants aren't different from what they are in real life is an unfortunate waste of brain power. It is a lost generation of an entire sub-discipline really. A tragedy of epic proportions that has set the discipline back because it got lazy about the scientific method. The same can be said for the multiverse people and the anthropic principle folks. It isn't just the Hierarchy Problem/Puzzle. It is the strong CP problem as well. It is the "fine tuning" problem. So are all variations of the question of whether something in physics is "natural." All of those misguided research agendas are devoted to solving problems that aren't really problems.

Understanding how the world works given the rules of the game that exist is an entirely different venture from asking why the rules of the game that exist are not different from what they are because you have a model that says that they should be different. The notion that the world really runs according to your flawed model and then is corrected in some undiscovered way is dubious at best and always has been.

The problem is a philosophical one to its core. There is no physics answer to why the fundamental constants of nature have the values that they do if you go deep enough, because at some point the question itself is nonsensical. We might, if we are lucky, determine that the 30 or so fundamental constants of physics can actually be reduced to some smaller number of fundamental constants N<30 because some of those constants may be functionally related to other constants. But, at some point, when you have a given set of fundamental constants, those just are the laws of Nature and there is no "why?" to ask.

Can you please share any references of other physicists who have the same views as yours above? But then.. your profile says you are a business lawyer... Were you a physicist before? Or just a physics enthusiast?