Froggatt & Nielsen: top-Higgs blobs explain everything

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Discussion Overview

The discussion centers on the proposals by Froggatt and Nielsen regarding nonperturbative top-Higgs effects and their implications for high-energy physics, particularly in explaining anomalies related to lepton universality and the existence of new bound states of top quarks. The scope includes theoretical interpretations, cosmological models, and experimental observations in particle physics.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants summarize Froggatt and Nielsen's approach to explain high-energy physics deviations from the Standard Model (SM) through nonperturbative top-Higgs effects, emphasizing the significance of the top Yukawa coupling.
  • Others reference a related paper discussing a cosmological model based on the Multiple Point Principle (MPP), which predicts degenerate vacua and implications for the Higgs boson and top quark masses.
  • There are claims regarding the observation of new bound states of top quarks, termed "T-fireballs," and their potential manifestation in LHC data, particularly in multijet production.
  • Some participants question the validity of Froggatt and Nielsen's predictions, specifically regarding the non-existence of the 750 GeV state and discrepancies in decay width predictions for H→γγ compared to experimental results.
  • Concerns are raised about the speculative nature of some predictions, suggesting that models must align with experimental data to be considered viable.
  • One participant identifies three distinct clusters of ideas in Froggatt and Nielsen's work: the MPP, new bound states of top quarks, and the explanation of lepton universality violations through top-Higgs interactions, noting their potential interconnections.
  • There is a detailed description of how lepton universality violations may arise from complex Feynman diagrams involving top-Higgs interactions, suggesting a departure from traditional perturbative approaches.

Areas of Agreement / Disagreement

Participants express a mix of support and skepticism regarding Froggatt and Nielsen's models. While some find merit in the proposed ideas, others challenge the validity of their predictions and the coherence of their theoretical framework. No consensus is reached on the effectiveness or correctness of the models discussed.

Contextual Notes

Limitations include unresolved questions about the accuracy of predictions, dependence on specific theoretical assumptions, and the need for further experimental validation of the proposed models.

mitchell porter
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TL;DR
Nonperturbative top-Higgs effects proposed to explain all violations of lepton universality
Summary: Nonperturbative top-Higgs effects proposed to explain all violations of lepton universality

Three years ago, Froggatt & Nielsen wanted to explain the, apparently spurious, 750 GeV resonance as top quarks bound, not just by the gluonic strong force, but also by the 'Higgs force', which for the top is also strong (top yukawa ~ 1).

Now they are back, aiming to explain most HEP deviations from the SM as due to nonperturbative top-Higgs effects:

https://arxiv.org/abs/1905.00070Colin D. Froggatt, Holger Bech Nielsen
(Submitted on 30 Apr 2019)

We interpret anomalies, deviations, from the standard model as being in fact due to effects not given by perturbation, because the top Yukawa coupling is after all so large that not by perturbation effects become important. Most of the anomalies found have the character of signaling violation of lepton universality. There are four lepton universality violating anomalies known at present, which we shall fit with one overall scale parameter to order of magnitude accuracy. One can look at the picture that we have found - due to the rather strong top Yukawa coupling - as a new sector of strongly interacting particles analogous to quantum color dynamics inside the standard model! [...]
 
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Another notable recent paper by one of the same authors and others:

arXiv:1801.06979

Degenerate Vacua of the Universe and What Comes Beyond the Standard Model

B. G. Sidharth, C. R. Das, C. D. Froggatt, H. B. Nielsen, Larisa Laperashvili

We present a new cosmological model of the Universe based on the two discoveries: 1. cosmological constant is very small, and 2. Nature shows a new law in physics called "Multiple Point Principle" (MPP). The MPP predicts the two degenerate vacua of the Universe with VEV v1≈246 Gev and v2∼1018 GeV, which provide masses of the Higgs boson and top-quark. A new cosmological model assumes the formation of two universal bubbles. The Universe at first stage of its existing is a bubble with a de-Sitter spacetime inside, having black-holes-hedgehogs as topological defects of the vacuum. Such a bubble has a "false vacuum" with VEV v2, which decays very quickly. Cooling Universe has a new phase transition, transforming the "false" vacuum to the "true" (Electroweak) vacuum. Hedgehogs confined, and the universal bubble is transformed into the bubble having spacetime with FLRW-metric and the vacuum with new topological defects of U(1)(el−mag) group: magnetic vortices and Sidharth's pointlike defects. The problem of stability/metastability of the EW-vacuum is investigated. Noncommutativity of the vacua spacetime manifold is discussed. The prediction of a new physics is given by the future observations at LHC of the triplet SU(2) Higgs bosons (at energies E∼10 TeV), and/or of the new bound states 6t+6t¯ formed by top-antitop quarks (at E∼1 TeV). The problem "What comes beyond the Standard Model" is discussed at the end of this paper.

Submitted 29 January, 2018; v1 submitted 22 January, 2018; originally announced January 2018.
Comments: 22 pages, 4 figures, Presented in International Conference "Physics 2018" on January 16, 2018 at "International Institute of Applicable Mathematics and Information Sciences, B.M. Birla Science Centre, Adarsh Nagar, 500063 Hyderabad, India"
 
Even more bold is that claim that top quark hadrons have been observed in the LHC data:

New indications of the existence of the 6 top-anti-top quark bound states in LHC experiments
C. D. Froggatt, C. R. Das, L. V. Laperashvili, H. B. Nielsen
(Submitted on 10 Dec 2012)
It was shown: 1) that the mass of the Higgs boson discovered by LHC corresponds to the stability conditions of the SM vacua and to the Multiple Point Principle, according to which all vacua of the SM are degenerate, or almost degenerate; 2) that early predicted by authors new bound states (NBS) of the 6 top and 6 anti-top quarks ("T-fireballs"), which are formed by their intermediate interactions with the Higgs bosons, manifest themselves in the production of multijets in pp-collisions at LHC. The CMS experiment of LHC with the production of 10 jets can be explained by the production of pairs of these NBS along with the production of pairs of the top-anti-top quarks. 3) Also it was shown that the next indication of the possible existence of the NBS can be the decay H→γγ, which was observed by CMS-collaboration of LHC. We have considered the contributions of the one-loop diagrams to the width ΓH→γγ, taking into account the contributions of the T-fireballs along the contributions of the known SM-particles.
Comments:23 pages, 7 figures, A talk submitted to the Conference "Quarkonium-2012", Moscow, Russia, RAS-MEPHI, November, 12 - 16, 2012
Subjects:High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
Cite as:arXiv:1212.2168 [hep-ph]
(or arXiv:1212.2168v1 [hep-ph] for this version)
 
Do they have an explanation for the non-existence of the 750 GeV state? They claimed it would appear from their approach, it is not there, so something must be wrong with their method.
ohwilleke said:
New indications of the existence of the 6 top-anti-top quark bound states in LHC experiments
These slides have a poor quality. Anyway, one numerical prediction they make is a H->gamma gamma decay width of 1.46 times the SM prediction. This is far away from more recent measurements.
 
mfb said:
Do they have an explanation for the non-existence of the 750 GeV state? They claimed it would appear from their approach, it is not there, so something must be wrong with their method.These slides have a poor quality. Anyway, one numerical prediction they make is a H->gamma gamma decay width of 1.46 times the SM prediction. This is far away from more recent measurements.

A lot of their predictions are speculative and prove to be incorrect.
 
Even speculative predictions can't disagree with experiment to be taken seriously. If the same model that might explain some b-physics anomalies leads to predictions elsewhere that are clearly incompatible with experimental results then that model has been ruled out. Next model, please.
 
I see at least three distinct clusters of ideas in this body of work by Froggatt, Nielsen, et al.

One is this "multiple point principle" of degenerate vacua, which (somehow) retrodicted the top mass and predicted the Higgs mass, within a few GeV, and which is now being given a cosmological form.

Then there is the idea of new bound states of top quarks held together by the Higgs force, owing to the top yukawa being of order 1.

Finally, there is the new proposal to explain violations of lepton universality, as being due to top-Higgs "blobs" which affect the heavier leptons more strongly, again via the yukawa coupling to the Higgs.

While these things are probably connected in the minds of Froggatt and Nielsen, and there would be some interest in understanding that perspective, it is also possible to treat them as logically independent, and my interest is primarily in the third idea, considered in isolation.

The blobs of the new proposal are not exactly the same as the bound states of the second idea. They are actually "very complicated very high order [Feynman] diagrams which, except for some smaller attachments to the studied particles, consist only of vertices of the top-Yukawa coupling type".

In other words, the violations of lepton universality will arise because the dominant processes are not the diagrams that usually appear in perturbative studies of lepton production in B-meson decay (etc), but rather, those same diagrams but intricately dressed in a web of top-Higgs interactions.

Judging by the sketch on page 11, these blobs are basically lots of top loops connected to each other and to other particles by Higgs propagators. Froggatt and Nielsen propose that the effects of the blobs can be summed up in EFT style by a few effective interaction terms, and that these can account for 4 or 5 BSM anomalies using just a single new parameter.

However, they are very far from being able to exhibit their proposed EFT. In fact, in the course of spelling out their ideas, they introduce a number of peculiar-looking concepts, like "dsb-quarks" and "linear combinations of quarks and their anti-quarks". These are supposed to be valid in the unfamiliar regime that they are trying to describe, and one thing I hoped to judge, was whether they do make sense or not.

But another topic of interest is whether a similarly unified explanation of the anomalies might be produced from a different foundation. In my studies, I mainly focus on explanations of the yukawas and so on, rather than on BSM anomalies, and I don't know if it's a routine thing for all the anomalies listed in part 2 of the paper, to receive a common explanation.
 

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