What are Preons and How Do They Fit into the Standard Model?

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Discussion Overview

The discussion centers on the concept of preons and their potential role within the framework of the Standard Model of particle physics. Participants explore various preon models, their implications for fundamental particles, and the theoretical underpinnings of these models, including their mathematical structures and predictions regarding particle properties.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants express skepticism about composite models of quarks and leptons, likening them to linguistic decompositions, while others advocate for their exploration, citing existing models like those developed by Carl Brannen.
  • Harari's model introduces two rishons, T and V, which combine to form all leptons and quarks, with specific combinations representing different particles and noting that baryon number and lepton number are not conserved individually, but their difference is conserved.
  • Fredriksson's model proposes three types of preons (A, B, C) with specific charges and combinations that form leptons and quarks, but does not provide a full explanation for mass.
  • Yershov presents a preon-based model where preons are treated as topological objects, suggesting that their structures can predict fermion masses with high accuracy without experimental input.
  • Another perspective from Yershov describes preons as having specific charges and masses, forming unstable doublets that lead to stable Y particles, which are further combined to create known particles, while also addressing the polarization of light through photon composition.
  • Participants note that the models discussed do not fully explain mass and raise questions about the implications of these models for existing particle physics frameworks.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the validity or applicability of preon models. There are multiple competing views regarding the structure and implications of preons, with some models being more widely accepted than others, but no definitive agreement on any single model.

Contextual Notes

Limitations include the dependence on specific definitions of preons, unresolved mathematical steps in the models, and the varying degrees of acceptance among participants regarding the implications of these models for established physics.

  • #31
In the spirit of algebraic preons, A. Zee presents a binary code (5 bits for the particles of a single generation) for the elementary fermions, in section VII.7, page 410-415, of his book "QFT in a nutshell". It comes from spinors, it meets the structure of some GUT groups, and it is generalised into a breaking SO(18) ---> SO(10) x SO(8).

Reference is given to Wilczek and Zee, Phys Rev D 25, p 553, section IV.
 
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  • #32
Those who waded through my paper on cosmic rays were likely either shocked or horrified to discover that it was about tachyons. It turns out that there was another paper that came out just before mine that went into some detail on the same subject:

Quantum Tachyon Dynamics
H. M. Fried, Y. Gabellini
http://arxiv.org/abs/hep-th/0505272

There are some startling similarities (but many more differences) between the above and my own efforts. Both papers suggest that tachyons are associated with high energy cosmic rays and gamma ray bursts. Their paper uses Schwinger's action principle as a basic formalism, while I use Schwinger's measurement algebra (i.e. primitive idempotents).

Carl
 
  • #33
http://arxiv.org/abs/hep-th/0501115

Authors: Igor A. Bandos
Comments: 30 pages, LaTeX, AIPProc style, Contribution to the Procs. of XIX Max Born Symposium. V2: References added, citations completed

We review briefly the notion of BPS preons, first introduced in 11-dimensional context as hypothetical constituents of M-theory, in its generalization to arbitrary dimensions and emphasizing the relation with twistor approach. In particular, the use of a 'twistor-like' definition of BPS preon (almost) allows us to remove supersymmetry arguments from the discussion of the relation of the preons with higher spin theories and also of the treatment of BPS preons as constituents. We turn to the supersymmetry in the second part of this contribution, where we complete the algebraic discussion with supersymmetric arguments based on the M-algebra (generalized Poincare superalgebra), discuss the possible generalization of BPS preons related to the osp(1|n) (generalized AdS) superalgebra, review a twistor-like kappa-symmetric superparticle in tensorial superspace, which provides a point-like dynamical model for BPS preon, and the role of BPS preons in the analysis of supergravity solutions. Finally we describe resent results on the concise superfield description of the higher spin field equations and on superfield supergravity in tensorial superspaces.

Also a 1992 monograph worthy of mention: http://www.worldscibooks.com/physics/1700.html

and a citation to a 1999 article:

http://www.sns.ias.edu/~adler/Html/preons.html

and 2004 stringy preons:

http://arxiv.org/PS_cache/hep-th/pdf/0409/0409146.pdf

and

http://arxiv.org/abs/hep-ph/0411313

Why quarks cannot be fundamental particles
Authors: C. S. Kalman
Comments: 3 pages - PDF file. to be published Proceedings of the 6th International Conference Hyperons, Charm and Beauty Hadrons
Journal-ref: Nucl.Phys.Proc.Suppl. 142 (2005) 235-237

Many reasons why quarks should be considered composite particles are found in the book Preons by D'Souza and Kalman. One reason not found in the book is that all the quarks except for the u quark decay. The electron and the electron neutrino do not decay. A model of fundamental particles based upon the weak charge is presented.
 
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  • #34
I think that the work of H. Terazawa should be mentioned in this thread. He as been proposing preon models for 30 years, and I have met his work when looking citations of other topics this year, such as Koide's formula or Hadronic (diquark) Supersymmetry. So it seems that he is very alert for rare developments.

This topic of hadronic supersymmetry, headed by Lichtenberg and by Catto, has a preonic scent in the sense that quarks are considered susy partners of composite particles, the composite consisting of pairs of...quarks again!
 
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  • #35
They should haved called the preon a "turtle" and killed two birds with one stone.
 
  • #36
thats right

Antiphon said:
They should haved called the preon a "turtle" and killed two birds with one stone.
thats right!
:devil: :devil: :devil:
 
  • #37
Antiphon said:
They should haved called the preon a "turtle" and killed two birds with one stone.
Now I get it :blushing: But indeed it could be also that the quarks themselves are the turtles, the hadrons being the elephants.
 
  • #38
Another question is how preons are related to composite higgs sector (topcolor etc). It seems that both developments are done separately, but if there are turtles in the fermion sector, what about the bosons then?

It could be interesting to remark again the observation of Hans about the quotient between W and Z0, that happens to be equal to the one between relativisit spin 1 and spin 1/2 composites (
 
  • #39
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  • #41
susy preon

A entertaining idea I have just read about, is to impose supersymmetry in the preons themselved. This is different of my guess about having susy between composite and elementary entities.
The funny point is that if you get a fermion as a composite of charge Qa, spin 0 and charge q2, spin 1/2, then the susy partner is again a equal charge fermion, composed of charge Qa spin 1/2 and charge Qb, spin 0 preons.
Now the minimal possibility is to use two supermultiplets, having each a spin 1/2 preon and two spin 0 preons (a susy multiplet always has equal number of fermionic and bosonic degrees of freedom). We have :frown: four generations:
fermion of the first multiplet and first boson of the second one
fermion of the first multiplet and second boson of the second one
First boson of the second multiplet and fermion of the second one
Second boson of the second multiplet and fermion of the second one
:shy:

One could try to mimick the observed spectrum by breaking susy, giving to the one of the fermions a higher mass so that two of the previous configurations are mistaken as if they were one. Also one could look for a mechanism to give masses to the composite particles in a way that the boson mass has different contribution that the fermion mass, so that again we could distiguish only three generations.

Even so, the model is a bit ugly: we need six particles (two susy multiplets) to explain three.
 
  • #42
Hrm

Electrons have no internal structure... think of an electron as a whirrling electric charge with nothing else inside

When the energizes of Positrons colliding with Electrons are added up, they do not violate the conservation of energy in that they are exactly equal as would be expected with the electron having no internal structure to jostle around.

E=[mc²]²+[pc]²

Dont forget about:
-the charm quark and strange quark.
-Conservation of strangeness in decay
-the breaking of parity symmetry in the Weak Force
-Quark Color
-The extremely small and variable mass of the muon tau and electron variety neutrinos.

I personally feel the SUSY theory to be a bit obsurb but who am I to say.
Actually, theories that I do not support are...

String Theory - Cannot stand the idea that energy(gravitons) leaks into other dimensions to never return...
SuperSymmetry
The Higgs Field - quite the strange theory to save the Quantum model.


Please let me know if I overlooked something.
 
  • #43
ChrisMelani said:
Electrons have no internal structure. Think of an electron as a whirrling electric charge with nothing else inside. When the energizes of Positrons colliding with Electrons are added up, they do not violate the conservation of energy in that they are exactly equal as would be expected with the electron having no internal structure to jostle around.

Classically, your argument is correct, but I think it fails in quantum mechanics. All the energy sum shows is that if electrons do have internal structure, then that structure is in its lowest energy state.

It's clear that using the weak force, one can arrange for an electron to be in a superposition with a muon or tau. In that case, one can suppose that there is something getting jostled around.

Carl
 
  • #44
ohwilleke said:
I'll just take a moment to summarize Fredriksson and Harari's models, since both are intriguing and delightful in their own ways (I'll deviate from standard notation and show antiparticles with lower case to save a lot of Texing):

Harari (April 1979): .

A way to check the impact of Harari-Shupe preons is to browse across spires:

http://www.slac.stanford.edu/spires/find/hep/www?rawcmd=FIND+C+PHLTA%2CB86%2C83+OR+C+PHLTA%2CB86%2C87&FORMAT=www&SEQUENCE=ds

or in citesummarial way

http://www.slac.stanford.edu/spires/find/hep/www?rawcmd=FIND+C+PHLTA%2CB86%2C83+OR+C+PHLTA%2CB86%2C87&FORMAT=wwwcitesummary&SEQUENCE=ds
 
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  • #46
CarlB, any news of the Sunday meeting? Nice people to recruit for Physics Forums, at least?
 
  • #47
This blog entry discuss preons in the context of an article of O.W. Greenberg

http://fysix.blogspot.com/2006/05/composite-matter-generation-number.html
 
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  • #48
arivero said:
CarlB, any news of the Sunday meeting? Nice people to recruit for Physics Forums, at least?

No, I'm afraid we will remain on the fringes for the moment.

As an update, arXiv put my April paper up again, in the "physics" classification, but I had them pull it. The version they gave is out of date and I'm too busy right now to go through the stuff required to replace it with the latest (MASSES2).

I'm still mulling through the Koide paper, particularly page 6: http://www.arxiv.org/abs/hep-ph/0605074 and am wondering about what this means. There are quite a lot of downloads of my MASSES2 paper that are undoubtedly due to the Koide paper.

Sorry for the long delay, apparently I am no longer getting emails when forums I've subscribed to get posts.

Carl
 
  • #49
CarlB said:
I'm still mulling through the Koide paper, particularly page 6: http://www.arxiv.org/abs/hep-ph/0605074 and am wondering about what this means. There are quite a lot of downloads of my MASSES2 paper that are undoubtedly due to the Koide paper.

This is interesting because it also implies that a lot of people is downloading last Koide paper (hey, I had missed it!). When you upload a paper to the arxiv the only statistics you can get is from citebase, that only uses hits to the uk mirror. Can you keep a log of the downloads, just for curiosity? If you are logging IPs, you can translate them to names using host or whois (or I can do it for you if you wish, it is a short script).
 
  • #50
arivero said:
This is interesting because it also implies that a lot of people is downloading last Koide paper (hey, I had missed it!). When you upload a paper to the arxiv the only statistics you can get is from citebase, that only uses hits to the uk mirror. Can you keep a log of the downloads, just for curiosity? If you are logging IPs, you can translate them to names using host or whois (or I can do it for you if you wish, it is a short script).

Well, I guess it depends on what the definition of "a lot" is. For me, it is around 1 or 2 downloads per day. There was about 14 or so on the day that the Koide paper hit arXiv. Sorry for not mentioning it, I thought it was well known, but in retrospect, the only reason I knew it had come out was because of the sudden increase in traffic.

I've got extensive records of DNS numbers for people who've downloaded my papers dating back a year or so. I'm traveling right now and don't have them in my laptop. Yahoo only allows you to keep the most recent 28 days and sometimes I forget for longer than that, so there are gaps.

I've always converted them by hand, mostly using this link:
http://www.dnsstuff.com/

Carl
 
  • #51
Ernest Ma in hep-ph/0606039 does a toast to preons when reviewing tribimaximal mixing, he says:
hep-ph/0606039 said:
Notice that the 3 vertical columns are evocative of the mesons \eta_8, \eta_1, \pi^0 in their SU(3) decompositions.
 
  • #52
CarlB said:
I'm still mulling through the Koide paper, particularly page 6: http://www.arxiv.org/abs/hep-ph/0605074

By the way, I wonder if the possibility of setting the vector (-\sqrt m_1 ,\sqrt m_2 ,\sqrt m_3) both at 45 degrees of (1,1,1) and at 90 degrees of (\sqrt{m_\tau},\sqrt{m_\mu},\sqrt{m_e}) (which is also at 45 degrees of (1,1,1) ) is ruled out by the phenomenology or on the contrary makes a good ansatz. This additional condition amounts to ask
\sqrt { m_1 m_\tau} =^? \sqrt{m_2 m_\mu}+\sqrt{m_3 m_e}
 
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  • #53
arivero said:
Ernest Ma in hep-ph/0606039 does a toast to preons when reviewing tribimaximal mixing, he says:

Nice observation. And it sort of fits in with my belief that the leptons are SU(3) singlets.

By the way, I'm not at all sure that "tribimaximal" has become a part of the usual physics terminology. In response to a question about Koide's paper, I got a response from a fairly famous physicist as follows: I don't regularly read hep-ph - and it may be completely unfair, but my mental crackpot filter would automatically balk at reading a paper whose title contains the word "tribimaximal".

Carl
 
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  • #54
arivero said:
By the way, I wonder if the possibility of setting the vector (-\sqrt m_1 ,\sqrt m_2 ,\sqrt m_3) both at 45 degrees of (1,1,1) and at 90 degrees of (\sqrt{m_\tau},\sqrt{m_\mu},\sqrt{m_e}) (which is also at 45 degrees of (1,1,1) ) is ruled out by the phenomenology or on the contrary makes a good ansatz. This additional condition amounts to ask

Lets to work out this. The ortogonality condition can we rewritten as
\sqrt { m_1} = \sqrt{m_2} \sqrt{ m_\mu\over m_\tau}+\sqrt{m_3} \sqrt{m_e\over m_\tau}

and then the 45 degrees condition
<br /> {-\sqrt{m_1} + \sqrt{m_2} +\sqrt{m_3} \over<br /> \sqrt{m_1+m_2+m_3} \sqrt{3}} = {1 \over \sqrt 2}<br />becomes
<br /> \sqrt{m_2} (1-\sqrt{ m_\mu\over m_\tau})+\sqrt{m_3} (1-\sqrt{m_e\over m_\tau}) = \sqrt \frac 3 2 \sqrt{ m_2 (1+{ m_\mu\over m_\tau}) + m_3 (1+{m_e\over m_\tau}) + \sqrt{ 2 m_2 m_3 { m_\mu m_e \over m_\tau^2} }}<br />

or
<br /> \sqrt{m_2\over m_3} (1-\sqrt{ m_\mu\over m_\tau})+\ (1-\sqrt{m_e\over m_\tau}) = \sqrt \frac 3 2 \sqrt{ {m_2\over m_3} (1+{ m_\mu\over m_\tau}) + \ (1+{m_e\over m_\tau}) + \sqrt{ 2 {m_2 \over m_3} { m_\mu m_e \over m_\tau^2} }}<br />
Hmm pretty unmanageable. Let's put numbers in...

<br /> .75615 \sqrt{m_2\over m_3} + .983042<br /> =\sqrt \frac 3 2 \sqrt{1.059459 {m_2\over m_3} + 1.00028756 + .0116954 \sqrt{ m_2 \over m_3} }
and
\sqrt { m_1\over m_3} = .24384 \sqrt{m_2\over m_3} + .016957

The question now, if the numbers are right, is to see if this ansatz is compatible with the measured oscillations

EDITED AGAIN: in principle it implies m2/m3=0.525,m1/m3=0.0375 (?) :sad: it does not seem to work
 
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  • #55
Hey, folks! Sundance preons are no longer fringe. Check out the cover of the August 12 New Scientist.

:smile:
 
  • #56
Kea said:
Hey, folks! Sundance preons are no longer fringe. Check out the cover of the August 12 New Scientist.

:smile:


Are you sure that being on the cover of New Scientist counts as non-fringe evidence?:wink:
 
  • #57
selfAdjoint said:
Are you sure that being on the cover of New Scientist counts as non-fringe evidence?

No, it doesn't really. But when more String theorists realize that one can describe moduli with ribbon diagrams, that will make a difference. It's a mystery to me why none of them have claimed the octopi for themselves via the connection with matrix models.
:smile:
 
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  • #58
some attachments

Some days ago, CarlB did some comment on meson masses, joking that he could try about searching Koide's formulae there.

Well, just in case, here attached is a C program do to it with the six basic charged mesons, plus the dump of the output for the general case of plus and minus square roots. Koide quotient is in the first column of data, the other thing are "angles against the diagonal" in six, n, and 3 dimensions, with N being the number of mesons involved in a particular calculation.

Input data is

Code: 
float mass[6] = {139.57018, /*pm0.00035*/
                 493.677, /*pm 0.016*/
                 1869.3, /*pm 0,4*/
                 1968.2, /*pm 0.5 */
                 5279.0, /*pm 0.5 */
                 6286    /*pm 5 */
                 };

Corresponding to pion, kaon, D, Dstrange, B, Bcharmed. In the listing I have used uppercase D and B for the stranged and charmed versions of d and b.

Program compiles as usual: gcc -lm koide.c -o koide
If you run it, you could want to sort -n -k 4, and perhaps to grep output.txt -v -

Most of the coincidences are artifacts coming from having pairs of particles with nearby mass, d D and b B. You could want to run some "null tests" with values having the same pattern, say {0.001,0.002,300,300,1000,1000}. Exact integer multiples (nor fractions), or near exact, are most probably artifacts.
 

Attachments

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  • #59
Why am I posting this in the thread of preons? Well, because, as veteran readers of PF know, I got the idea last year of having the preons directly from quarks: a pair of quarks would compose a boson, and then this boson is supersymmetrically transfomed to the fermion we are aiming for. Sort of bootstrap.

I described the idea one year ago in hep-ph/0512065. It is not bad, it produces only a extra degree of freedom in the neutrino sector and six horrible 4/3 coloured degrees of freedom in a quark/antiquark sector, but I would hope they can be eliminated on the grounds of representation theory.

It has the adventage that we know the masses of the, er, subquarks, and also we know how they bind: with SU(3) colour. The binding via SU(3) colour gives some substance to infrarred mass relationships, as Koide's, that are troublesome to be planted in the GUT scale (albeit some people do). Ideally the IR limit of QCD explodes the coupling constant, and then justifies the trick.

But the problem is that we already have the "susyleptonic" sector of this theory, and they are the charged mesons of the previous post. It is not a badly broken thing, because the pion has more of less the same mass than muon and the D particles are about the same mass than the tau. But the electron has no partner near, neither the B particles.

So here is why I think it is unlikely to find Koide relationships for mesons: because I think that in the limit of unbroken supersymmetry, leptons would derive Koide relationship from the fact they are partners of sleptons, which happen to be mesons, thus composites. In this limit, then, mesons also meet Koide relationships, and furthermore they are degenerated in pairs. But I find unlikely that Koide can survive in both sectors after symmetry breaking, and if it survives in leptons, my guess is that it will break in the mesonic part.

Telling this, and against myself, I can not but notice that besides the obvious triplets (0, m_\pi, m_{D_s}) and (0, m_\pi, m_{D}), also the triplet (0, m_k, m_{B_c}) is, unexpectedly,very Koide-like. Moreover, when the 0 is substituted by another of the particles, D or B, it counterweights nicely, climbing Koide's relation from 2:3 to 2:5.
 
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  • #60
Upps I just realized, I am asking for strong coupling of QCD, so I am asking for strong coupling of the QCD string. What does happens to strings at strong coupling? It rings a bell in my head as if someone has spoken a lot about it...