Fact Check, debunking obviously false information

Quote from JulianBianchi

Except this paper is not a review. Here is a review: https://arxiv.org/pdf/1709.0492

Not good that cross sections calculated by perturbative QCD change so much from LO to NLO to NNLO and now with N3LO corrections. This does not give much credence to the underlying model. Furthermore, this only applies to high-energy physics, because perturbation theory and with it the concept of force-mediating particles fail in low-energy QCD, bound states, solitons, etc...

Perhaps we use the word review in different ways?

Your review has 23 references.

My review has 217 references.

Length, number of citations, vary similarly.

More specifically., your review is looking at one particular issue in the comparison of experimental data and one specific set of MC generators used to perform computations in lattice QCD for specific LHC 2017 analysis.

My review is looking at a general change in methodology (adding NLLx small-x resummation) that improves fit across a wide range of experimental datasets - comparing this with previous work.

I don't see (other than linguistics) any argument, except that your review is clearly not suitable as an overall review of the merits and demerits of 2017 work in this area. Maybe mine, because focussing on the NLLx resummation, is also not suitable, but it does give more insight.

If you argue that QCD calculations are so mired in complexity that it is difficult to be sure they are right - then I'd agree with you. This however is a criticism of the computation and not the theory. It does reflect badly on the theory to the extent that the uncertainty makes it less predictive in those areas where calculation is difficult (most). So I accept your concern that the calculations are not great, but not that the underlying model is therefore wrong. I'm also not saying the underlying model is the final word, or even particularly satisfactory. But, however messy, it has a lot of predictive power other than the computationally horrible determination of parton distributions in quark-heavy space.

One way to think about this is that SM provides a unified and extremely successful model for all known particle physics - with the exception of dark energy and matter that seem necessary from cosmological considerations but are not (currently) relevant to particle physics. In this model precise calculations work well except for QCD where the perturbative expansions are not nice for understandable computational reasons. That makes QCD less predictive (at the moment - unless/until we develop better computational techniques). When it becomes more predictive maybe it will prove more clearly wrong or right.

Physicists crave simplicity. I've never though that it is reasonable also to crave computational simplicity. Why should God have made the workings of the universe easily calculable? you might almost (in a theological context) take extreme computational complexity as God's way of giving us all free will - though this is not a theological site and many people would less subtly invoke HUP as that.

Low energy QCD. Still WIP. But:

https://arxiv.org/abs/1810.07720

Looks promising.

Quote from Alan Smith

So it works for 5% of the apparent matter in the universe. That's alright then. You overlook that fact that we all agree the SM and QM are useful engineering models, but so is Newtonian mechanics. It just isn't perfect.

Hi Alan,

let us just say it works for everything we can perform experiments on?

I agree, there is lots of other stuff out there - it seems. It is a bit difficult to tell with all the cosmological stuff exactly because you can make observations, but not perform experiments.

Here, for those interested, is a nice self-contained (if you know QFT) tutorial description of QCD: explaining the various renormalisation and calculation issues.

https://www.hep.ucl.ac.uk/postgrad/teaching/sm/SMIIL6.pdf

Quote from Curbina

We, or at least I, acknowledge your expertise in the complexities of SM mathematical modeling and its experimental and computational verification.

However, some, slowly but steadily becoming more, already think SM will become obsolete after the more widely applicable SO(4) model, which is also mathematically and computational very complex, but less distant from experimental values, becomes more developped and widely known.

Well, no I'm not expert in that. Could be if I worked hard at it for 3 years.

I'll be interested in SO(4) model when it has any significant predictive success, or if it seems to be neat theoretically and capable of encompassing the breadth of phenomena explained by SM. Neither of those apply to what I've read so far.

Quote from THHuxleynew

It seems from your reply above that you do not understand QM, do not understand QFT. And therefore classify it as "not real". That is your privilege, but it is a shame and excludes you from evaluating the last 50 years of physics. Can I ask have you actually learnt the math for QM and the QFT? All that linear algebra? Because without that I don't think you can fairly evaluate either.

Are you talking to me? I understand the maths of QFT. And I can fairly evaluate it. Enough to tell you this: it falls at the first hurdle. QED claims photons don't interact with photons, when they do. See the Wikipedia two-photon physics article. It originates from the HEP group at UCL and says this: “From Quantum Electro Dynamics (QED) we know that photons cannot couple directly to each other, since they don’t carry charge, but they can interact through higher order processes: a photon can, within the bounds of the uncertainty principle, fluctuate into a charged fermion/anti-fermion pair, to either of which the other photon can couple”. It's abject nonsense. A 511KeV photon does not magically morph into a 511keV electron and a 511keV positron. That’s in breach of conservation of energy. In similar vein a 511keV electron and a 511keV positron cannot magically morph back into a single 511keV photon. That’s in breach of conservation of energy and conservation of momentum. Moreover photons travel at the speed of light whilst electrons and positrons don’t. So if a photon did somehow manage to fluctuate into a fermion pair and back again, it couldn’t be travelling at the speed of light. And most importantly of all, pair production doesn't occur because pair production occurred! Spontaneously! Just like that! SNAP!

Quote

"only exist in maths of the model". Sure, that is true of all reality as described by modern physics. What makes a QM wave looking like an photon more "real" than a QFT disturbance looking like a virtual photon? Both are math constructions with precise observable effects. Both are abstract.

What? Photons are not abstract. Compton scattering is real. The photoelectric effect is real. The electron is real too. And when you understand the electron, you understand why it moves the way that it does. And it isn't because virtual photons are popping in and out of existence like magic.

Quote

Don't teach grandma to suck eggs? I'm sure most people here know that particle/wave duality is satisfactorily resolved with wave packets.

I will hold your nose to this grindstone until I see a scintilla of understanding from you.

Quote

QM means you don't have to choose. So, given you accept this, and we agree, why not accept disturbances in quantised fields as as virtual particles? Too modern for you? I realise QFT was not nearly as easy historically as QM (which itself was not that easy).

Because virtual particles are virtual. Because they don't exist. Messenger particles do not exist. I've already told you that an electron goes round in circles in a magnetic field because spin is real, and subject to Larmor precession. There are no unseen virtual photons popping in and out of existence.

Quote

Well it accords (as a popularisation) well with my (now 40 years old) understanding. And Matts better description is pretty precise. While I do not claim to be an expert, having studied this stuff so long ago, Gordan Kane can reasonably so claim, as can Matt Strassler. I don't accept proof by authority but I'd need more than "appalling garbage" and links to either outdated science, or outlying science from authors who have clearly never learnt the math to understand the theory you claim they are replacing, either because it did not yet exist in a fully coherent form (Lamb, Rutherford), or because (Schaeffer) they have never learnt it.

You're clinging to conviction. Those guys aren't experts, and I'll give you a lot more than "appalling garbage". See this post where I referred to Maxwell's 1871 paper? Where he combined convergence and curl? I then gave a depiction of the electromagnetic field. Now think about positronium. Why do the electron and the positron move towards one another and around one another? Because Maxwell was barking up the right tree with his theory of molecular vortices. Because counter-rotating vortices attract. And because the electron is a "dynamical spinor":

CCASA positronium image by Manticorp, spinor motion image by me

Quote

I'm sympathetic with people who have fully understood modern QFT, and can solve problems in it, want something better and try to find it. There are a lot of those. But not your links from people who have not done that.

Are you sympathetic to page 26 of Schrödinger’s quantization as a problem of proper values, part II? Schrödinger said let us think of a wave group “which in some way gets into a small closed ‘path’, whose dimensions are of the order of the wave length”.

Quote

You are asserting one magical mathematical model over another (also magical, but emerging directly from theory that applies to many other physical things, and therefore more fundamental) model. Why? In what way is magnetic moment more real than a virtual photon?

I'm not asserting some "magical mathematical model". I'm dispelling the mysticism of the magical mathematical model. Magnetic moment is real because the torque is real. Things really do go round and round. The Einstein-de Haas effect is real. Have a read of Hans Ohanian's 1984 paper what is spin? He said “the means for filling the gap have been at hand since 1939, when Belinfante established that the spin could be regarded as due to a circulating flow of energy”. Frederik Belinfante’s paper was on the spin angular momentum of mesons.

Quote

Look, that is a very strong claim about a prolific theoretical physicist who has published a lot of relevant papers. How many of his (peer reviewed) papers have you read, and how many have you succeeded in rebutting or adding to? With peer reviewed refs please.

It's a strong claim and it's true. I can't recall reading any of Matt Strassler's papers. Let's have a look on the arxiv. What have we got? Metastable supersymmetry breaking and multitrace deformations of SQCD dating from 2009. No thanks. My interest is real physics, not fantasy physics.

Quote

You are stuck in the past.I'm not. I just prefer to read the original material instead of the popscience fairy tales.

I'm not. See for example Art Hobson's explanation of the double slit experiment in his 2013 paper There are no particles, there are only fields. It starts on page 12.

Quote

I take (as popular account of strong force understanding as of 2 years ago John Butterworth (he wrote a book too)

https://www.theguardian.com/sc…uclear-force-a-revelation

There's no understanding of the strong force here.

Quote

and the relevant review: https://arxiv.org/abs/1710.05935 (published as Eur.Phys.J. C78 (2018) no.4, 321)

Now, the maths here is complex. I'll accept the "it is rubbish" opinion from anyone who can do it (and has done so) - but not from those who have not. And I'll accept that it (the above review) is not nonsense, because

(1) it gets through peer review in a major journal

(2) It gets a lot of (peer reviewed major journal) citations https://inspirehep.net/search?…efersto%3Arecid%3A1631169

This paper isn't explaining the strong force in any way. It's talking about parton distribution, Why are you even referring to it? Because it's been peer reviewed and it has citations? Weinberg's paper has over sixteen thousand citations. That doesn't make it right. It doesn't model the electron at all.

Quote

That means a lot of people who have learnt and done calculations with the relevant theory have read it and not trashed it. (You can check the citations if wondering whether they mostly say it is nonsense).

But did any of them ask the obvious question? Where do all those partons go in low-energy proton-antiproton annihilation to gamma photons?

Annihilation images from CSIRO Australia Telescope National Facility

Quote

Now - I'd agree that strong interaction is "unsolved" in the sense that not all questions about it can be calculated. The calculations are unpleasant. But I'll not accept that it is "not explained". The model does explain it nicely, does allow calculations that are predictive. I'll not accept that "all the models create too little or no intermediate range attraction".

It isn't explained at all. If you beg to differ, explain it.

Quote

Philosophically - I'd also not accept that forever unpleasant calculations make a theory wrong or even incomplete, though equally I'd always hope for better calculation methods in the future.

I hope you're not going to tell me to shut up and calculate. I will not.

Quote

I'd accept Machleidt17 (as a personal but not unreasonable view) but not your summary of his conclusions:

Thus, chiral EFT may ultimately suffer the same fate as meson theory. As explained in Sections 1 and 2, meson theory was originally (Phase I) designed to be a quantum field theory, but later (Phase II) had to be demoted to the level of a model (a very successful model, though). During the current Phase III, the main selling point has been that chiral EFT is a theory and not just a model and, therefore, its dogmatic use has been pushed. However, in analogy to what historically happened to meson theory, during the next phase (namely, Phase IV), we may have to resign ourselves to chiral EFT based models (that may potentially have great success). The history of nuclear forces clearly shows a pattern of 30-year phases. Whether these cycles will go on forever or whether Phase IV will be the last one, we will know Anno Domini 2050.

His paper (https://arxiv.org/abs/1710.07215) misses the trick. The nuclear force is electromagnetic. Electron capture does what it says on the tin.

Quote

And I'd agree that QCD is work in progress - partly because so computationally complex, it makes working out what is true slower.

A decent forward-looking paragraph (with broader context) from Laura Marcucci

Nuclear force between nucleons can be seen as a residual force resulting from the constituents of the nucleons, i.e., the quarks. How this force is connected with QCD has been an intense field of research since many decades. Thanks to lattice QCD and to the advent of chiral effective field theory (for recent reviews see [2, 3]), we are in the process of building nuclear interaction on the strong basis of QCD. Some issues however remain unsolved and definitely constitute grand challenges for NP: while the nucleon-nucleon interaction is nowadays quite well under control, the same cannot be said for the three-nucleon force, for which at the moment exist far less sophisticated models. This reflect on some long-standing discrepancies between theory and experiment in few-body observables, as the well known “Ay puzzle” (see [4] and references therein). The solution of this puzzle is a grand challenge for NP. The situation is even worse for the hyperon-nucleon and hyperon-hyperon interactions, for which lot of work still needs to be done. This is ultimately related to the “hyperon-puzzle” in neutron stars [5], which will be discussed below.

If this is true, how come there's no diprotons and no dineutrons? There are no proton-proton nuclei, and no neutron-neutron nuclei either.

Quote

One thing I don't accept is that systems like nuclei which are known to be highly complex many-body systems should (in a final GUT) necessarily have simply calculable properties. In fact I'd say we know enough to see why the known interactions (whether you use a quark model or something equivalent) are likely to be difficult to calculate. That does not (to me) seem a defect of the model.

Fine. But if you want to understand a nucleus, you have to understand the proton first. And to understand the proton, it helps if you understand the electron. But when you do, you come to appreciate that much of the Standard Model is wrong.

Quote

I fully expect something deeper than the SM to emerge from a GR / QFT unification that explains spacetime. I don't expect that such will make calculations of complex many-body systems in QCD any easier. Will we end up with a much easier way of calculating this stuff? Open question.

Spacetime is an abstract mathematical thing that models space at all times. We live in a world of space and motion. The map is not the territory. And I expect something deeper to sweep away the Standard Model. I'm not sure what you'd call it. Maybe TQFT. Maybe electromagnetic geometry. Maybe something else.

Quote

I guess the amplitudehedron story gives us some hope.

It's pseudoscience. Forget it.

It's worth to note, that even classical mechanics has its own "many worlds" interpretations, for example this one in Huyghens and/or Fermat principle. It's not accidental, because quantum mechanics also follows Hamilton mechanics.

Quote from THHuxleynew

One way to think about this is that SM provides a unified and extremely successful model for all known particle physics - with the exception

SM did give us a particle catalog based on spin, flavor, color, charge what I name the Quark,Yoghurt, Bidfidus model. SM did not give us a method to calculate any single quantity of any particle based on first principle as this is a corollary of the missing magnetic gauge.

SO(4) physics is a first successful model - based on higher EM symmetry - that shows all connections between all 4 classic forces and stable particles and their quantities like mass, magnetic moment, charge radius with an average 9 digit precision.

When I started to read in SM papers I had the impression to read "findings" of people with a strong mental distortion writing fantasies to recover an unfindable meaning from a heuristic religious like model. After three months I stopped and declared it fringe science.

There is a lot of useful engineering in the so called SM mountain of collected experience like good approximations for muon decay -predictions for high energy scattering etc... Thus do not confuse SM with what it claims to be.

SM is not fundamental - is a corollary of the missing magnetic gauge of QM - SM is not even explanatory it's just descriptive and approximative good old engineering school nothing more.

Are you talking to me? I understand the maths of QFT. And I can fairly evaluate it. Enough to tell you this: it falls at the first hurdle. QED claims photons don't interact with photons, when they do. See the Wikipedia two-photon physics article. It originates from the HEP group at UCL and says this: “From Quantum Electro Dynamics (QED) we know that photons cannot couple directly to each other, since they don’t carry charge, but they can interact through higher order processes: a photon can, within the bounds of the uncertainty principle, fluctuate into a charged fermion/anti-fermion pair, to either of which the other photon can couple”. It's abject nonsense. A 511KeV photon does not magically morph into a 511keV electron and a 511keV positron. That’s in breach of conservation of energy. In similar vein a 511keV electron and a 511keV positron cannot magically morph back into a single 511keV photon. That’s in breach of conservation of energy and conservation of momentum. Moreover photons travel at the speed of light whilst electrons and positrons don’t. So if a photon did somehow manage to fluctuate into a fermion pair and back again, it couldn’t be travelling at the speed of light. And most importantly of all, pair production doesn't occur because pair production occurred! Spontaneously! Just like that! SNAP!

DF - I was wondering whether you had studied QM (let alone QFT) because you make basics mistakes like the one you repeat above. You argue that conserved quantities are necessarily conserved through the intermediate states in a reaction - when we all know that is not true, or tunneling could not occur. The paragraph you quote actually points this out, mentioning HUP, which you seem not to consider?

DeltaE * DeltaT ~> h/4pi

Thus a transient short-lived intermediate state can exist with energy much higher than the (equal - from conservation of energy) long-term energy of the constituents or the reactants.

So - the idea that photons can couple with each other through higher order processes is very natural.

DF: What? Photons are not abstract.

A self-propagating disturbance in electric and magnetic fields (which are themselves mathematical constructs) seems pretty abstract to me.

Now - the effect of e-m radiation is concrete. As are the effects of the field disturbances called virtual particles.

My point was not really about whether you choose to call the mathematical models we use in particle physics (and give concrete names) real or abstract. It is that you are inconsistent considering some real and others not real.

Anyway, can I suggest we agree to disagree until such time as you come to understand that in a quantum world conservation of energy cannot be applied on short timescales(my post above).

Quote from THHuxleynew

Thus a transient short-lived intermediate state can exist with energy much higher than the (equal - from conservation of energy) long-term energy of the constituents or the reactants.

Only if it borrows the missing energy from somewhere else!

Quote from Wyttenbach

SM did give us a particle catalog based on spin, flavor, color, charge what I name the Quark,Yoghurt, Bidfidus model. SM did not give us a method to calculate any single quantity of any particle based on first principle as this is a corollary of the missing magnetic gauge.

SO(4) physics is a first successful model - based on higher EM symmetry - that shows all connections between all 4 classic forces and stable particles and their quantities like mass, magnetic moment, charge radius with an average 9 digit precision.

When I started to read in SM papers I had the impression to read "findings" of people with a strong mental distortion writing fantasies to recover an unfindable meaning from a heuristic religious like model. After three months I stopped and declared it fringe science.

There is a lot of useful engineering in the so called SM mountain of collected experience like good approximations for muon decay -predictions for high energy scattering etc... Thus do not confuse SM with what it claims to be.

SM is not fundamental - is a corollary of the missing magnetic gauge of QM - SM is not even explanatory it's just descriptive and approximative good old engineering school nothing more.

Display More

Strong claims. But, alas, without the validation of properly written (to be comprehensible to others) papers I cannot judge what is the substance behind these brave words.

The standard model gives us 3 symmetry groups and corresponding particle properties, with predicted conservation laws. Then further, it gives us a way to calculate a whole load of relationships and parameters, based on Feynman diagrams or equivalent. All of this comes from a very small conceptual basis, and the success - in terms of predicted physics - is enormous.

Now - if you accepted that, and said you had something that was equivalent to SM (almost everywhere) replicating that structure - but with added value, or even just with a more fundamental theoretical rationale - I'd be highly interested.

As I understand it you are saying that it is all wrong, as a theory, and you have a different starting point. But, in that case, I need first to see how you can replicate the (correct) SM calculations for almost everything. That is a tough call, the easiest way to do it would be to show precisely how (perhaps given some assumptions) the SM, which does correctly make all those predictions, can be derived from your work.

When I started to read in SM papers I had the impression to read "findings" of people with a strong mental distortion writing fantasies to recover an unfindable meaning from a heuristic religious like model. After three months I stopped

Can I suggest that three months is not enough time to learn particle physics? That you cannot know the merits and demerits of SM based on such brief acquaintance? And finally that your belief that so much of the particle physics community is subject to "strong mental distortion writing fantasies" is unlikely true, but quite possibly projection?

THH

Quote from THHuxleynew

As I understand it you are saying that it is all wrong, as a theory, and you have a different starting point. But, in that case, I need first to see how you can replicate the (correct) SM calculations for almost everything.

Please do stop such jokes. SM cannot and will never be able to calculate anything close to exact from first principle because of the missing magnetic gauge! If you refer (precision) to the electron g-factor fraud paper, then I understand your logic.

So far you failed to show us anything else where SM could calculate some quantity with e.g. 5 digits precision without ad-hoc fudging.

"As I understand it you are saying that it is all wrong, as a theory." (You did obviously not read all text...) --> I say it's incomplete and as engineering model it is sometimes useful, but it is not a basic theory of physics and will never be one.

Quote from Wyttenbach

Only if it borrows the missing energy from somewhere else!

I am now highly surprised W - I will have to reconsider my opinion of you. This is quite serious.

No - tunnelling occurs without borrowing energy from anywhere else. Reactions with transient intermediate products work on the same principle.

Mathematically it perhaps easiest to take a very concrete example, an electron in a potential well with finite height sides. The electron does not have enough energy to escape the confines of the well but it does of course manage eventually to do this. If we look at why, we can see that the wave function (spatial basis) shows a non-zero value at energies above the actual energy of the electron. This indicates that there is some probability of the electron having this elevated energy - because momentum (and hence energy) is imprecise in a spatially constrained box. There is no problem with conservation of energy because if we look at the long-term probability-weighted average all is good.

When considering intermediate stages of reactions you will I am sure know that reaction cross-sections are got by integrating the joint probability distribution of the constituents multiplied by the probability of reaction occurring. We therefore get a non-zero cross-section for excess energy intermediates; as long as they can get down fast enough to a stable long-term state that does obey the energy constraint. (My example is slightly inexact because it is too complex here to consider non-stationary wave functions, as is of course needed to see how the time dependence of the intermediate state affects the overall probability. Mathematically the interacting portion of the wave function has an exponential time decay dependent on the excess energy for as long as it is in a long-term forbidden energy state).

My point seems well proven: I'm all for people who understand existing successful theories pointing out their defects and coming up with something better, which may perhaps seem very different.

But, without an adequate understanding of what existing theories mean, any attempt to replace them will be unphysical - because those existing theories encode in a compact form so very much experimentally validated physics.

It is no good looking at little corner cases where the theory looks wrong, and rejecting the whole thing, because you need all the rest (which works) in order to summarise in a compact from all that physics which any replacement must also predict.

missing magnetic gauge

I'm not entirely sure what you mean here - but you do realise that there is no fundamental distinction between electric and magnetic fields, don't you? They are reference-frame specific. There is just an electromagnetic 4-vector which is Lorentz-invariant. Perhaps by "magnetic gauge" you mean something different.

So it works like this:

electric and magnetic fields -> em 4-vector

em 4-vector dynamics drops out of the electroweak langrangian.

it is all lorenz invariant (modulo phase)

A nice summary of SM as a gauge theory based on SU(3) X SU(2) X U(1) broken spontaneously to SU(3) X U(1)

https://arxiv.org/pdf/hep-ph/0502010.pdf