Sabine Hossenfelder on the search for new particles

[Frabjous]

The goal of an op-ed is to provoke is a serious discussion. Looking at the previous 70 posts, I think she mostly succeeded.

 

[Astronuc]

Another take on Hossenfelder's article and related blog(s) -
https://www.cnet.com/science/are-pa...-new-particles-for-no-reason-its-complicated/
Jackson Ryan, CNET's science editor, ponders "Are Particle Physicists Inventing New Particles for No Reason? No, but It's Complicated"

In a nutshell, Hossenfelder says that theoretical particles are being conjured up out of thin air to explain some of the anomalous findings physicists have seen in particle colliders and high-energy physics experiments. She contends that an entire "zoo" has been invented featuring an array of strange particles like "wimps," "axions" and "sterile neutrinos."

As she notes in her piece, particle physicists have been looking for the inhabitants of the "zoo," but experiments designed to find them haven't discovered anything. So, she writes, researchers are wasting time looking for made-up particles beyond the Standard Model, which she believes "works just fine the way it is." Many particle physicists disagree with that idea, noting in particular that it doesn't describe dark matter.

Speaking to particle physicists over the last week, it's clear Hossenfelder's claims rankled the field.

Many view the framing of Hossenfelder's article as unfair. Some believe it simply contains mistruths and false information. The major concern I've heard is how Hossenfelder presents particle physicists working "in private" as if they've been acting conspiratorially, keeping the truth about their work from the public.

Hossenfelder points out she used to be a particle physicist and has now "left the field." This distance, she writes, renders her "able and willing to criticize the situation." However, it may leave readers thinking that basically every working particle physicist is somehow untrustworthy.

Interesting analogy follows.

Hossenfelder has been rattling cages in physics for some time. She has questioned whether big particle colliders, like the one that may replace the Large Hadron Collider, should be built at all because we haven't found these new particles scientists have been predicting for decades.

Hossenfelder's skepticism of scientific results and theories is absolutely warranted. Science is about refining our understanding over time as new results yield new insights. In this way, Hossenfelder's critiques of particle physics can be helpful.

Hossenfelder's piece paints the field of particle physics with one very broad brush, suggesting "thousands" of tenured professors are "ambulance chasing" and operating in secret, some sort of shady cabal that exists purely to continue existing and siphoning up research money. Particle physicists I spoke with disagreed with these generalizations.

However, the practice of "ambulance chasing" Hossenfelder calls out in her piece is something that's worth exploring.

This puts a lot of pressure on scientists to publish and particularly affects those early in their careers and from diverse backgrounds. As the funding for scientific research dwindles, as it has in places like Australia, that pressure grows. Scientists get caught in the cycle of publishing to stay in a job. They're fighting each other to survive.

I've seen the pressure to publish, something I see at work. And I've seen stiff competition for limited funding (and some politics behind it).

 

[Vanadium 50]

I always thought a bosun was a member of the ship's crew but now I know better

During my qualifying exam oral, I was asked "So, tell us about supersymmetry". I started, "It's a theory where every partner has a superpartner differing by 1/2 a unit of spin. For example, every boson has..." and I blanked on the word "fermion" and all I could think of was "boson's mate".

 

[Vanadium 50]

Why do all the other fermions receive their mass by Yukawa coupling with the Higgs field and the neutrinos don't?

They might very well. There is nothing prohibiting a neutrino getting a Dirac mass via a Higgs Yukawa. And indeed, this is what people were writing pre-SuperK and SNO. But this is probably best discussed on another thread - ideally the one where I was posting what people were writing pre-SuperK and SNO.

 

[strangerep]

I agree that it is poorly written, and largely defensive.

... which is perhaps why her article should be put in proper context. I.e., she wrote it in response to a fresh series of attacks against her. See her more recent response here. In particular:

[...] As a consequence of these recent insults targeted at me, I wrote an opinion piece for the Guardian that appeared on Monday. Please note the causal order: I wrote the piece because particle physicists picked on me in a renewed attempt to justify continuing with their failed methods, not the other way round.

 

[PAllen]

Another take on Hossenfelder's article and related blog(s) -
https://www.cnet.com/science/are-pa...-new-particles-for-no-reason-its-complicated/
Jackson Ryan, CNET's science editor, ponders "Are Particle Physicists Inventing New Particles for No Reason? No, but It's Complicated"

Interestingly this article refers to her as a former physicist. As I noted earlier this is absurd - 4 papers published in reputable peer reviewed journals in 2022 so far is an admirable productivity rate for a physicist.

 

[malawi_glenn]

Interestingly this article refers to her as a former physicist. As I noted earlier this is absurd - 4 papers published in reputable peer reviewed journals in 2022 so far is an admirable productivity rate for a physicist.

A former PARTICLE physicist, was one of the headlines.
Maybe the author of the article at hand (Jackson Ryan) did not bother to check that up.
Or "Has the entire field of particle physics collapsed, thanks to the efforts of a former physicist who is now speaking out?"
is just an interpretation/re-statement of the said headline?
In the next paragraph, the author is referring to her as "astrophysicist"

The controversial takes have often led to unjustified personal insults and harassment for Hossenfelder by other scientists.

Never read any of those. If there is no source, it might as well be made up

 

[martinbn]

... which is perhaps why her article should be put in proper context. I.e., she wrote it in response to a fresh series of attacks against her. See her more recent response here. In particular:

Can we see those attacks or do we have to take her word for it?

 

[vanhees71]

I think Hossenfelder has a general point: In the history of physics progress in theory building has never come from pure speculations but was indeed always grounded in either discrepancies between observations and theories/models or in inner-theoretical problems. Of course, it's not always easy to answer, whether something is really an inconsistency between experiment and theory or whether there are errors on both sides. To figure this out, is among the prime tasks in the daily work of scientists, and there's no recipy to be followed to be successful, but it's a creative act for both experimentalists and theorists to have the right ideas.

I think she is wrong concerning the prediction of the C quark, which was indeed proposed to avoid neutral flavor-changing currents (on the tree-level) in electroweak theory, i.e., clearly based on experimental findings, leading to the famous GIM mechanism. Of course her other arguments (freedom of anomalous gauge-symmetry breaking) are as well valid.

Particularly, I never understood, why there is a "measurement problem in quantum theory". For me the opposite is the case: QT is so successful concerning the agreement between theory and experiment that there cannot be any measurement problem, because obviously we have a mathematical formalism with a suffcient interpretation enabling this "success" of QT. The minimal statistical interpretation without any unnecessary philosophic ballast seems to me the most scientific one, but all the others are not much worse, because they lead, usually by construction, to the same scientific predictions. I think thus at this point Hossenfelder contradicts herself, because this apparent "measurement problem" is neither a discrepancy between experiment and theory nor a inner-theoretical inconsistency. It's simply a pseudo-problem based on age-old philosophical prejudices about the indeterministic Nature of QT. So following Hossenfelder's definition of a "good problem" there's be no reason to think about this pseudo-problem to begin with.

What are real problems with QT are that QFT has still no solid mathematical foundation, i.e., it's basically only perturbatively defined, which is a inconsistency of the fundamental theory and the lack of a satisfactory quantum treatment of the gravitational interaction, and here when following Hossenfelder's definition of a "good problem" you'd conclude that one shouldn't work on this problem at all, because we have empirical hints towards the right prediction.

I think the mistake is to think that there's a fail-safe method to find out, which research programs (both theoretical and experimental) lead to success, and one must find a good balance between pretty safe investments funding "standard science projects", where one can be pretty sure to make some progress in some fundamentally well-understood field and "high-risk projects", where it is unlikely but possible to find something really new. Whether or not it makes sense to spend some billion of $ for a new particle collider, is hard to say. So it's a well-justified strategy to have made the newest LHC upgrade for more luminosity and the corresponding upgrades to the established detectors to exploit it for high-precision measurements. In my own field (relativistic heavy-ion collisions) I also think the planned electron-ion collider is a logical next step forward in a relatively safe sense to clarify some open questions in the field.

 

[malawi_glenn]

New anomalies routinely produce hundreds of such papers over a few weeks with a long steady drip afterwards.

That is true, which I mentioned. But overall, it is a small percentage.

The problem is that physicists waste a lot of time studying dubious models that would be better spent elsewhere. This is a problem whether the papers get published or not. The time spent writing the papers and the time by others reading the papers (who waits until publication to read papers anymore?)

Physicists also waste a lot of time eating, sleeping, watching TV, playing video games, reading spiderman comics. I for instance spent during my PhD 3000 hours in the gym.

 

[Vanadium 50]

. I for instance spent during my PhD 3000 hours in the gym.

Excellent plan:

 

[pinball1970]

That is true, which I mentioned. But overall, it is a small percentage.

Physicists also waste a lot of time eating, sleeping, watching TV, playing video games, reading spiderman comics. I for instance spent during my PhD 3000 hours in the gym.

2 ¾ hours per day?
Every day for three years?

Was your PhD thesis, “Training for the high energy physicist?”

 

[malawi_glenn]

Every day for three years?

PHD in sweden is 4 years, but yes about 2h/day, 6 times/week. Lots of warm ups, stretching etc. Also bringing in/out strongman equipment and so on, and helping others to train.

 

[ohwilleke]

Why is this parameter $\theta$ identical to zero in this term in the QCD lagrangian? $\theta F_{\mu \nu} \tilde F {}^{\mu \nu}$

Either it is identical to zero just by pure chance, or its very very very close to zero and we have not yet been able to experimentally to measure it (not enough statistics), or there is symmetry/mechanism for setting it to zero (axion models), or we do not understand how quantum Yang-Mills theories work. All of these options, except the first one, are open for scientific investigation.

What value parameter a physical constant of nature has is a physics problem.

Why it has that value instead of another one in a counterfactual version of reality is not a "problem". Maybe it's natural philosophy, but it isn't science.

 

[ohwilleke]

Particularly, I never understood, why there is a "measurement problem in quantum theory". For me the opposite is the case: QT is so successful concerning the agreement between theory and experiment that there cannot be any measurement problem, because obviously we have a mathematical formalism with a suffcient interpretation enabling this "success" of QT. The minimal statistical interpretation without any unnecessary philosophic ballast seems to me the most scientific one, but all the others are not much worse, because they lead, usually by construction, to the same scientific predictions. I think thus at this point Hossenfelder contradicts herself, because this apparent "measurement problem" is neither a discrepancy between experiment and theory nor a inner-theoretical inconsistency. It's simply a pseudo-problem based on age-old philosophical prejudices about the indeterministic Nature of QT. So following Hossenfelder's definition of a "good problem" there's be no reason to think about this pseudo-problem to begin with.

The "measurement problem" at its most tepid is how to determine what constitutes a "measurement" in a less subjective and more rigorously defined way.

 

[ohwilleke]

Excellent plan:
View attachment 314953

This is why in Finland they don't give you a sword until after you are awarded your PhD. (They also give you a funny hat.)

 

[ohwilleke]

One of the things she rejects as a good research area is the origin of matter/antimatter asymmetry. We should just chalk it up to initial conditions. This one I find quite absurd.

"Baryon Asymmetry and The Horizon Problem
These are both finetuning problems that rely on the choice of an initial condition, which is considered to be likely. However, there is no way to quantify how likely the initial condition is, so the problem is not well-defined."

from: "http://backreaction.blogspot.com/2019/01/good-problems-in-foundations-of-physics.html"

On what physical ground should the initial mix of baryons and anti-baryons be identical? This is merely an axiom with no basis to support it. The existing theory and observational evidence point to a non-zero initial baryon number.

 

[ohwilleke]

That is true, which I mentioned. But overall, it is a small percentage.

If I had to guess, I'd put it about about 20%-30% of hep-ph (and maybe 10-15% of hep-ex).

(Note that I guessed the percentage before doing the count below.)

It may not be an insurmountable problem, but it is pretty significant.

These recent examples (selected based upon the Op-Ed criterion, I'm sure I may have missed one or two and may have misclassified one or two but it is pretty close to the mark) make up 38 of the last 160 (23.75%) of "recent" hep-ph papers at arXiv:

arXiv:2209.15544
Constraining extended scalar sectors at current and future colliders -- an update
arXiv:2209.15098
Quark mass generation due to scalar fields with zero dimension
arXiv:1703.08798
Light axion-like dark matter must be present during inflation
arXiv:2209.14882
Light thermal relics enabled by a second Higgs
arXiv:2209.14870
Sensitivity of the FACET experiment to Heavy Neutral Leptons and Dark Scalars
arXiv:2209.14867
Dilaton Effective Field Theory
arXiv:2209.14659
Heavy Neutral Leptons Beyond Simplified Scenarios
arXiv:2209.14605
Gravitational wave signals from leptoquark-induced first order electroweak phase transitions
arXiv:2209.14404
SM Extension With Gauged Flavor U(1)F
arXiv:2209.14343
Sommerfeld enhancement of resonant dark matter annihilation
arXiv:2209.14318
Analytic approach to ALP emission in core-collapse supernovae
arXiv:2209.14305
Relic Challenges for Vector-Like Fermions as Connectors to a Dark Sector
arXiv:2209.14268
Asymptotically safe dark matter with gauged baryon number
arXiv:2209.14246
The Type II Dirac Seesaw Portal to the mirror sector: Connecting neutrino masses and a solution to the strong CP problem
arXiv:2209.13888
Exploring maverick top partner decays at the LHC
arXiv:2209.13755
One-loop calculations for H→ff¯γ in the U(1)B−L extension for Standard Model
arXiv:2209.13653
A two-component vector WIMP -- fermion FIMP dark matter model with an extended seesaw mechanism
arXiv:2209.14061
Bounds from multi-messenger astronomy on the Super Heavy Dark Matter
arXiv:2209.13588
NASDUCK SERF: New constraints on axion-like dark matter from a SERF comagnetometer
arXiv:2209.13572
Probing Axions via Light Circular Polarization and Event Horizon Telescope
arXiv:2209.13566
Non-standard neutrino interactions in light mediator models at reactor experiments
arXiv:2209.13469
Probing right-handed neutrinos dipole operators
arXiv:2209.13466
Signatures of excited monopolium
arXiv:2209.13389
Family Non-universal Z′ Effects on Bd,s→K∗0K⎯⎯⎯⎯∗0 Decays in Perturbative QCD Approach
arXiv:2209.13266
Global fits of simplified models for dark matter with GAMBIT I. Scalar and fermionic models with s-channel vector mediators
arXiv:2209.13093
Top partners and scalar dark matter -- a non-minimal reappraisal
arXiv:2209.12947
Anomalous and axial Z' contributions to g-2
arXiv:2209.12909
Axion detection with phonon-polaritons revisited
arXiv:2209.12901
Discovering QCD-Coupled Axion Dark Matter with Polarization Haloscopes
arXiv:2209.13445
Improved Mixed Dark Matter Halo Model for Ultralight Axions
arXiv:2209.12802
Search for Majoron at the COMET Experiment
arXiv:2209.12780
Drell-Yan production in third-generation gauge vector leptoquark models at NLO+PS in QCD
arXiv:2209.12552
Neutron Star Heating in Dark Matter Models for Muon g-2 with Scalar Lepton Partners up to the TeV Scale
arXiv:2209.12281
The anomalous shift of the weak boson mass and the quintessence electroweak axion
arXiv:2209.12121
On the W mass anomaly in models with right-handed currents
arXiv:2209.12063
On the viability of a light scalar spectrum for 3-3-1 models
arXiv:2209.11780
Probing high-energy solar axion flux with a large scintillation neutrino detector
arXiv:2209.11773
Strong Supernova 1987A Constraints on Bosons Decaying to Neutrinos

 

[PAllen]

On what physical ground should the initial mix of baryons and anti-baryons be identical? This is merely an axiom with no basis to support it. The existing theory and observational evidence point to a non-zero initial baryon number.

If the initial number of baryons is zero, and they come to being from some other field, any SM production process will produce only a tiny asymmetry. If you believe a model of this type (as most cosmologists do) then it is simply wrong to treat this as a question of initial conditions.

 

[PAllen]

What value parameter a physical constant of nature has is a physics problem.

Why it has that value instead of another one in a counterfactual version of reality is not a "problem". Maybe it's natural philosophy, but it isn't science.

Throughout the history of our understanding of the universe, if something is allowed, it happens - unless there something we don’t yet understand that prevents it. This is why it is wrong to view this as a parameter value issue. QCD allows CP violation. By all prior experience we shoud expect it to occur unless there is something disallowing it - and that is worth understanding. Plus, as I noted previously, it is even possible that the resolution of this is related to baryon asymmetry. And this is NOT a question of initial conditions unless you accept that Sabine’s way of looking at physics is the only permissible way. The way I look at things has baryon asymmetry not even remotely a question of initial conditions.

 

[ohwilleke]

The way I look at things has baryon asymmetry not even remotely a question of initial conditions.

Baryon asymmetry is an issue only if one assumes an initial condition based upon conditions that do not flow from any empirically tested physical theory.

 

[ohwilleke]

If the initial number of baryons is zero, and they come to being from some other field, any SM production process will produce only a tiny asymmetry. If you believe a model of this type (as most cosmologists do) then it is simply wrong to treat this as a question of initial conditions.

Why should the initial number of baryons be zero? Nothing we have observed compels or even directs us to that conclusion. The fact that lots of scientists think it is pretty that way isn't a scientific answer.

 

[PAllen]

Why should the initial number of baryons be zero? Nothing we have observed compels or even directs us to that conclusion. The fact that lots of scientists think it is pretty that way isn't a scientific answer.

Because you have an era when quarks don’t exist yet. You may not like such a model, but for those who do, you cannot even pose baryon asymmetry as an initial conditions question. Instead you must have a creation process that favors quarks over anti quarks. I believe most cosmologists favor such models. Sabine first rejects such models without stating or explaining it, before she can even pose the question of initial conditions.

 

[PAllen]

Baryon asymmetry is an issue only if one assumes an initial condition based upon conditions that do not flow from any empirically tested physical theory.

No early cosmology theory can ever be tested under early conditions. We do the best we can.

 

[strangerep]

Can we see those attacks or do we have to take her word for it?

Hmm -- as if personal attacks were something that one should spread.

I'm out.

 

[Hornbein]

Returning to the original topic:

Jerry Pournelle's Iron Law of Bureaucracy is that the main goal of any institution will eventually change. Solutions for the problem it was created to solve will be pushed aside. The true purpose will become to preserve and increase the income of this organization. I don't see that physics is any worse in this regard than anything else. Do to its small size it is certainly relatively harmless. As to Sabine's efforts, I can't say it any better than did the Bobby Fuller Four.

 

[malawi_glenn]

Hmm -- as if personal attacks were something that one should spread.

I'm out.

Then we are back to "me too" movement, no proofs required.

Why it has that value instead of another one in a counterfactual version of reality is not a "problem". Maybe it's natural philosophy, but it isn't science.

So you have no interest in all to know why the photon mass is zero? After all, it might just be a paramter that is exactly zero. Or why electric conductivity for some materials become 0 below a certain temperature? As I wrote earlier, physics is also about finding patterns. Would just be stamp collection otherwise. I bet we would not have special or general relativity with this mindset

If I had to guess, I'd put it about about 20%-30% of hep-ph (and maybe 10-15% of hep-ex).

I was referring to "2sigma" anomalies papers. Not the other cathegories mentioned.

 

[PAllen]

Then we are back to "me too" movement, no proofs required.

During the "string wars" she did post a long series of horrific posts by supposedly serious physicists on her blog, that she deleted from the main blog, but posted separately for documentation. I have no doubt she has received vile posts due to her current critiques. As noted above, I disagree substantially with much of her current critique, but more so with anyone who responds inappropriately.

 

[vanhees71]

The "measurement problem" at its most tepid is how to determine what constitutes a "measurement" in a less subjective and more rigorously defined way.

There is nothing subjective in what our experimental colleagues do when investigating quantum phenomena but a well-defined setup of preparation and measurement devices, which can be objectively verified and reproduced (at least in principle).

 

[Roza]

For example, why do we need Dark Energy? The recession of galaxies can be explained by known physical phenomena. And gravity, using also known quantum phenomena and some more.

 

[pinball1970]

For example, why do we need Dark Energy? The recession of galaxies can be explained by known physical phenomena. And gravity, using also known quantum phenomena and some more.

https://en.wikipedia.org/wiki/Accelerating_expansion_of_the_universe

 

[ohwilleke]

There is nothing subjective in what our experimental colleagues do when investigating quantum phenomena but a well-defined setup of preparation and measurement devices, which can be objectively verified and reproduced (at least in principle).

"Our experimental colleagues" work well away from the gray areas.

For the same reason, the well known theoretical inconsistencies between the Standard Model and General Relativity which are widely accepted to exist in the scientific community don't impede much work with either theory because most experimental and observational work happens in domains where one or the other is the dominant effect, even though there are circumstances (e.g. at the event horizons of Black Holes) where the way that these theoretical inconsistencies are resolved has observable consequences.

But there are circumstances in which a rigorous definition matters that are not well explored with experimental or observational evidence (and it doesn't take $100M+ USD experiments and a cast of hundreds or more to investigate those issues experimentally).

For some of the relevant work see, e.g.: Matteo Carlesso, Angelo Bassi, "Current tests of collapse models: How far can we push the limits of quantum mechanics?" arXiv (January 27, 2020) published in Quantum Information and Measurement (QIM) V: Quantum Technologies; OSA Technical Digest (Optical Society of America, 2019), paper S1C.3 DOI: 10.1364/QIM.2019.S1C.3 and related scientific work discussed in Bob Henderson, "The Rebel Physicist on the Hunt for a Better Story Than Quantum Mechanics" New York Times (June 25, 2020) (also citing to https://arxiv.org/abs/1909.11301 by overlapping authors which has since been published at 53 J. Phys. A: Math. Theor. 215302 (2020)).

 

[ohwilleke]

No early cosmology theory can ever be tested under early conditions. We do the best we can.

If we can't test it, it isn't science. It is speculation, perhaps informed speculation, perhaps natural philosophy. But nothing more. Some questions are unanswerable, at least with available technology and knowledge.

The discipline might be better served by more humility about what we know or can know, and less guesswork.

 

[ohwilleke]

Returning to the original topic:

Jerry Pournelle's Iron Law of Bureaucracy is that the main goal of any institution will eventually change. Solutions for the problem it was created to solve will be pushed aside. The true purpose will become to preserve and increase the income of this organization. I don't see that physics is any worse in this regard than anything else.

Pretty much true, but not an argument against trying to improve the status quo. Bureaucracies are subject to external constraints including the economic resources available to the scientific enterprise. So, there are always going to be outside pressures to be less wasteful. Whether the outside pressures are sufficiently strong to overcome the problems partially depends on the priorities of the leaders in the community of physicists.

 

[Maarten Havinga]

The discipline might be better served by more humility about what we know or can know, and less guesswork

So true! It's good to remain open to new ideas on cosmology and critical of your own preferred view.