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

[arivero]

I do not like composite models of quarks and leptons; they seem to me just as decomposition of phonemes: it can be done, but it is not linguistic. Still, I could be wrong. Another PF inhabiatant, Carl Brannen, likes them enough to have developed his own model. And I'd guess he is not the only one around here.

So I would like to use this thread first to review the work already done and published on "preon" models. Some papers are old, thus sometimes it helps to search for them in spires instead of ArXiV because, beside extensive citation search, Spires keeps pointers to the KEK, Fnal and CERN preprint services. You can go to Spires from any ArXiV:hep- preprint by clicking the SLAC-SPIRES HEP tag.

The main spires trick is "find a Einstein and date 1905"

A first clue, because it is recent, is Sverker Fredriksson Preon Prophecies by the Standard Model, hep-ph/0309213. It points us to papers from Harari, Shupe, and Fritzsch.

The one from Harari is in KEK scans, at http://ccdb3fs.kek.jp/cgi-bin/img_index?7905333 I believe to remember that Harari work was about three non commuting preons with nice jewish names.

 

[ohwilleke]

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):
Two rishon (which means "primary" in Hebrew). They are T (Third for charge 1/3e or Tohu from "unformed" in Hebrew in Genesis) and V (Vanishes for charge 0 or va-Vohu which means "void" in Hebrew in Genesis). All leptons and all flavors of quarks are three rishon combinations. Three preon groups have spin 1/2.

TTT=positron.
VVV=electron neutrino
TTV, TVT and VTT=three colors of u quarks.
TVV, VTV and VVT=three colors of d antiquarks.

Each rishon has antiparticles. Hence:

ttt=electron
vvv=anti-electron neutrino
ttv, tvt, vtt=three colors of anti-u quarks
vvt, vtv, tvv=three colors of d quarks.

Baryon number (B) and lepton (L) number are not conserved, but B-L is conserved.

A Baryon number violating process would be U+U-->d+positron which in rishons is:
TTV+TTV --> TVV+TTT

Matter and anti-matter are equally abundant in nature.

The W+=TTTVVV
The W-=tttvvv

Higher generation leptons and quarks are presumed to be excited states of first generation leptons and quarks. Mass is not explained.

Fredriksson (September 2003):

Three kinds of preons. I'll depart from his Greek notation and render them as ABC for the preons and abc for the anti-preons. A and B have charge +1/3 C has charge -2/3. Preons have spin 1/2. Unlike preons have spin zero.

Leptons and quarks are three preon combinations. They are further broken into a lone preon and a dipreon in each case:

Leptons:
Electron neutrino A(BC)
Electron B(BC)
Muon A(AC)
Mu-Neutron B(AC)
Tau Neutrino A(AB)
Tau B(AB)

Proposed First Kappa Neutrino C(BC)
Proposed Second Kappa Neutrino C(AB)
Proposed Kappa Electron C(AC)

Quarks:
u=A(bc)
d=B(bc)
s=A(ac)
c=A(ab)
b=B(ab)
t=C(ab)

Proposed h=C(bc)
Proposed g=C(bc)
Proposed X=B(ac) (charge -4/3, possibly unphysical)

No Higgs particles. Bb dipreons can annihilate and produce Aa dipreons.

Weak Carrier Bosons:
W+=Ab
W-=Ba

Z and proposed Z'=Aa
Proposed Z' and Z=Bb
Proposed Z" and proposed Z'=Cc
Proposed Z*=Ac
Proposed z*=Ca
Proposed W+'=Cb
Proposed W-'=Bc

Mass is not fully explained.

 

[ohwilleke]

Another preon paper: http://es.arxiv.org/abs/physics/0207120

Fermions as topological objects
Authors: V. N. Yershov
Comments: Latex2e, 20 pages, 12 figures, 3 tables, (V8: formulae compactified)
Subj-class: General Physics

A preon-based composite model of fermions is discussed. The preon is regarded as a topological object with three degrees of freedom in a dual (3+1)-dimensional manifold. It is shown that dualism of this manifold gives rise to a set of preon structures, which resemble three families of fermions. The number of preons in each structure is readily associated with its mass. Although just a sketch, our model predicts masses of fermions to an accuracy of about $10^{-6}$ without using experimental input parameters.

 

[ohwilleke]

Yershov (March 2003):

Fundamental Particles:

The fundamental particle is the Preon, which has a charge of -1/9th in electron units. A Preon has a mass of 1/9th in electron units. Preon antiparticles also exist. Preons come in three colors (red, green and blue, if you like).

First Order Structure:

Preons can form charged or neutral doublets. Doublets are not stable. They promptly form Y particles composed of three preons, one of each color (in my notation "Y"), or three anti-preons, one of each color (in my notation "y"). A Y particle has a charge and mass of one third of an electron. Y particles have one preon on each color but are polarized (like a water molecule) with one color more prominent than the others.

Higher Order Structure:

First Generation
Electron Neutrino=6Yy (36 preons, 0 charge, 0 mass)
Electron=3y (9 preons, -9 charge, 9 mass)
Y*=Electron Neutrino+Y (39 preons, -3 charge, 39 mass)
U=y*,Electron Neutrino,y* (114 preons (39+36+39), +6 charge, 78 mass (39+39))
D=U,Electron Neutrino,Electron (114+36+9=159 preons, -3 charge, 78+36+9=123 mass)

Second Generation
Mu Neutrino=Y*,Electron Neutrino, y*
Muon=Mu Neutrino+Electron Neutrion,Electron
C=y**+y**
S=C+Electron

Third Generation
Tau Neutrino=U,Electron Neutrino, u
Tau=Tau Neutrino+Mu Neutrino+Muon
T=y***+y***
B=T+Muon

Note: a Y**=U,Electron Neutrino,U,Electron Neutrino,Electron and
a Heavy Neutrino=6Y*y*, and an Ultra Heavy Neutrino=3(y*,Heavy Neutrino,U),Electron and a Y***=an Ultra Heavy Neutrio,Y

Photons
It appears from the notation, although the author doesn't quite come out and say it, that a photon=Yy, but has no mass or charge because the antiparticles has a mass that cancels out. This does, however, appear to explain the polarization of light (see equation 10 at page 9 and the table at page 12).

Comment:

This model is notable because:
(1) It predicts the masses of all known particles to considerable accuracy. Of course, it also correctly assigns spin and charge numbers to all known particles.
(2) The model used a formula to determine the mass of composite particles which is not simply a sum of masses, which is along the line of the sum of the component part masses divided by the sum of the reciprocal masses of the particles. Neutrally charged neutrino components do not contribute significantly to mass -- Y's and y's has masses that almost completely cancel out.
(3) The model predicts the left handedness of the neutrino and the asymmetry between the lifetimes of para-positronium and ortho-postronium.
(4) Six kinds of Ys (one for each color and charge combination, all with the same charge and mass magnitude) are used to produce left and right handed versions of eight kinds of particles (three Y*s, three anti-Y*s, electrons, positrons), electron neutrinos, anti-electron neutrinos, and two polarizations of photons for a total of 20 kinds of particles.
(5) This model assumes that the world is made up of equal amounts of matter and anti-matter at the Y particle level.
(6) Gravity appears to be delegated to the curvature of space, a la GR.
(7) While charged preon doublets are considered confined, neutral preon doublets (i.e. a preon and its antipreon) are suggestively labeled $$g^0$$ suggesting that they are candidates for the gluon. The $$g^0$$ would, like the photon, be massless and chargeless, and would consist of both a preon and an anti-preon, with three possible colors each.

Table For My Favorite G,pi,e theorist

Predicted Mass (preon units;mass of proton=1 units) Experiment
electron=9 preon units; 0.0005446175 mp; 0.0005446170232(12) mp
u quark=78 preon units; 0.004720019 mp; 0.0047 mp
d quark=123 preon units; 0.007443106 mp; 0.0074 mp
muon=1860.9118 preon units; 0.11260946 mp; 0.1126095173 (34) mp
c quark=27122.89 preon units; 1.641289 mp; 1.6 mp
s quark=2745.37 preon units; 0.1661307 mp; .16 mp
tau=31297.11 preon units; 1.893884 mp; 1.8939(3) mp
t quark=3122289 preon units; 188.9392 mp; 189 mp
b quark=75813.33 preon units; 4.587696 mp; 5.2 mp

mp/me=1836.1510 vs. 1836.1526675(39) experiment

 

[ohwilleke]

More Yershov: http://es.arxiv.org/abs/physics/0301034

Date: Thu, 16 Jan 2003 09:54:57 GMT (18kb)
Date (revised v2): Fri, 7 Mar 2003 18:07:30 GMT (18kb)

Neutrino masses and the structure of the weak gauge boson
Authors: V.N.Yershov
Comments: LaTex2e, 4 pages (V2: minor linguistical corrections)
Subj-class: General Physics

It is supposed that the electron neutrino mass is related to the structures and masses of the $W^\pm$ and $Z^0$ bosons. Using a composite model of fermions (described elsewhere), it is shown that the massless neutrino is not consistent with the high values of the experimental masses of $W^\pm$ and $Z^0$. Consistency can be achieved on the assumption that the electron-neutrino has a mass of about 4.5 meV. Masses of the muon- and tau-neutrinos are also estimated.

Comment:

Basically, the assumption is that the composite mass formula for bosons is the inverse of the composite mass formula for fermions. The preon formulas for W+, W-, and Zo is set forth and the entire scheme in briefly recapped in a page or so. The experimental value of the W under the boson formula is used to establish the Z and neutrino masses, which should be nearly neutral under the original rest mass formula used for fermions.

The W-=electron neutrino, electron.
The W+=electron neutrino, postitron.
The Z=W+,W-.

 

[ohwilleke]

Search abstracts (body) in `astro-ph,cond-mat,gr-qc,hep-ex,hep-lat,hep-ph,hep-th,math-ph,nucl-ex,nucl-th,physics,quant-ph' in all years (1991-2005) for occurrences of `Preon'
(28 matches) :
1. hep-ph/0503213 [abs, ps, pdf, other] :
Title: A topological model of composite preons
Authors: Sundance O.Bilson-Thompson
Comments: 9 pages, 3 figures, submitted to Phys. Lett. B


2. hep-th/0501115 [abs, ps, pdf, other] :
Title: BPS preons in supergravity and higher spin theories. An overview from the hill of twistor appraoch
Authors: Igor A. Bandos
Comments: 30 pages, LaTeX, AIPProc style, Contribution to the Procs. of XIX Max Born Symposium. V2: References added, citations completed


3. astro-ph/0410417 [abs, ps, pdf, other] :
Title: Preon stars: a new class of cosmic compact objects
Authors: J. Hansson, F. Sandin
Comments: 10 pages, 3 figures


4. hep-th/0312266 [abs, ps, pdf, other] :
Title: On BPS preons, generalized holonomies and D=11 supergravities
Authors: I.A. Bandos, J.A. de Azcarraga, J.M. Izquierdo, M. Picon, O. Varela
Comments: 11 pages, RevTeX Typos corrected, a short note and references added
Journal-ref: Phys.Rev. D69 (2004) 105010


5. hep-th/0308065 [abs, ps, pdf, other] :
Title: Little Groups of Preon Branes
Authors: H.Mkrtchyan, R.Mkrtchyan
Comments: LaTeX, 11 pages
Journal-ref: Mod.Phys.Lett. A18 (2003) 2665-2672


6. hep-th/0212174 [abs, ps, pdf, other] :
Title: Brane Content of Branes' States
Authors: Ruben Mkrtchyan
Comments: Misprints removed, text improved
Journal-ref: Phys.Lett. B558 (2003) 205-212


7. hep-ph/0208135 [abs, ps, pdf, other] :
Title: Preon Trinity - A Schematic Model of Leptons, Quarks and Heavy Vector Bosons
Authors: Jean-Jacques Dugne, Sverker Fredriksson, Johan Hansson
Comments: 7 pages, epl.cls included, to be publ. in Europhysics Letters
Journal-ref: Europhys.Lett. 57 (2002) 188-194


8. physics/0207120 [abs, ps, pdf, other] :
Title: Fermions as topological objects
Authors: V. N. Yershov
Comments: Latex2e, 20 pages, 12 figures, 3 tables, (V8: formulae compactified)
Subj-class: General Physics


9. hep-th/0201233 [abs, ps, pdf, other] :
Title: Generalized Supersymmetries and Composite Structure in M-Theory
Authors: J. Lukierski (Wroclaw University, Inst. of Theor. Phys.)
Comments: LaTeX, 7pages. Talk presented at the XVI-th Max Born Symposium ,,Supersymmetries and Quantum Symmetries `01" (21-25.09.2001, Karpacz, Poland) and International Nankai Symposium (8-11.10.2001, Tianjin, China). To be published in the Proceedings of Nankai Symposium, Ed. Ge Mo-Lin and J. Park, Int. J. Mod. Phys. B
Journal-ref: Int.J.Mod.Phys. B16 (2002) 2039-2046


10. astro-ph/9912555 [abs, ps, pdf, other] :
Title: The Cosmological Consequences of the Preon Structure of Matter
Authors: Vladimir Burdyuzha (1), Grigory Vereshkov (2), Olga Lalakulich (2), Yuri Ponomarev (1) ((1) Astro Space Center of Lebedev Physical Institute of Russian Academy of Sciences, Moscow, Russia, (2) Rostov State University, Rostov on Don, Russia)
Comments: LaTex 2.09, 9 pages


11. hep-ph/9909569 [abs, ps, pdf, other] :
Title: Preon Trinity - a new model of leptons and quarks
Authors: Jean-Jacques Dugne, Sverker Fredriksson, Johan Hansson, Enrico Predazzi
Comments: 12 pages Latex, no figures; to be published in the Proceedings of Beyond 99, Tegernsee, Germany, June 1999


12. hep-ph/9907531 [abs, ps, pdf, other] :
Title: Preons, Dark Matter and the Production of Early Cosmological Structures
Authors: V. Burdyuzha (1), O. Lalakulich (2), Yu. Ponomarev (1), G. Vereshkov (2) ((1) Astro Space Center of Lebedev Physical Institute of Russian Academy of Sciences, (2) Rostov State University)
Comments: LaTeX 2.09, 13 pages, 1 Postscript figure


13. hep-ph/9901234 [abs, ps, pdf, other] :
Title: Quarks, Leptons as Fermion-Boson Composite Objects and Flavor-Mixings by Substructure Dynamics
Authors: Takeo Matsushima
Comments: 37 pages, 3 figures


14. hep-ph/9810494 [abs, ps, pdf, other] :
Title: Unity of Forces at the Preon Level with new Gauge Symmetries
Author: M.K.Parida (Phys.Dept.,North Eastern Hill Univ.,Shillong, India)
Comments: 41 pages, Latex, with five figures, To appear in Phys.Rev.D58(1998)
Journal-ref: Phys.Rev. D58 (1998) 115006


15. astro-ph/9804219 [abs, ps, pdf, other] :
Title: Highest Energy Cosmic Rays
Author: Paul H. Frampton
Comments: 6 pages. LaTeX. Talk at PASCOS-98, Northeastern University


16. hep-ph/9712522 [abs, ps, pdf, other] :
Title: The Excess of HERA High$-Q^2$ Events and Leptoquarks in a Left-Right Symmetric Preon Model
Authors: Motoo Sekiguchi, Hiroaki Wada, Shin Ishida (Atomic Energy Research Institute, College of Science and Technology, Nihon University)
Comments: 7 pages
Journal-ref: Prog.Theor.Phys. 99 (1998) 707-712


17. hep-ph/9712422 [abs, ps, pdf, other] :
Title: The Mystery of Flavor
Authors: R. D. Peccei (UCLA)
Comments: 23 pages, 2 figures, latex document


18. hep-ph/9712328 [abs, ps, pdf, other] :
Title: Proposal of unified fermion texture
Authors: W. Krolikowski (Warsaw Univ.)
Comments: 29 pages, LaTeX, no figures
Journal-ref: Acta Phys.Polon. B29 (1998) 755-782


19. hep-ph/9711433 [abs, ps, pdf, other] :
Title: Vacuum structure, spectrum of excitations and low-energy phenomenology in chiral preon-subpreon model of elementary particles
Authors: O.E.Evnin
Comments: 20 LaTeX pages, 8 figures


20. hep-ph/9711342 [abs, ps, pdf, other] :
Title: A Composite Model of Quarks with the `Effective Supersymmetry'
Author: Nobuchika Okada
Comments: 22 pages, uses REVTEX macro, revised manuscript to be published in Prog. Theor. Phys
Journal-ref: Prog.Theor.Phys. 99 (1998) 635-648


21. hep-ph/9709227 [abs, ps, pdf, other] :
Title: Higgs Pain? Take a Preon!
Authors: J.-J. Dugne, S. Fredriksson, J. Hansson, E. Predazzi
Comments: The preon contents of some quarks and leptons have been changed in order to achieve a more consistent scheme. A few new comments have been added. 13 pages, LaTeX, no figures. To be published in Proc. of the Meeting on 'The Fundamental Structure of Matter' and 'Tests of the Electroweak Symmetry Breaking', Ouranoupolis, Greece, May 1997


22. astro-ph/9709080 [abs, ps, pdf, other] :
Title: Longevity and Highest-Energy Cosmic Rays
Authors: Paul H. Frampton, Bettina Keszthelyi, Y. Jack Ng
Comments: 8 pages, RevTeX
Journal-ref: Int.J.Mod.Phys. D8 (1999) 117-122


23. hep-ph/9611343 [abs, ps, pdf, other] :
Title: A Supersymmetric Composite Model of Quarks and Leptons
Authors: Markus A. Luty, Rabindra N. Mohapatra
Comments: 10 pages, LaTeX 2e
Journal-ref: Phys.Lett. B396 (1997) 161-166


24. hep-th/9610190 [abs, ps, pdf, other] :
Title: Frustrated SU(4) as the Preonic Precursor of the Standard Model
Author: Stephen L. Adler
Comments: 36 pages, plain TEX, no figures


25. hep-ph/9603437 [abs, ps, pdf, other] :
Title: Need for Two Vectorlike Families in SUSY Composite Models
Author: H. Stremnitzer (Univ. of Vienna)
Comments: 6 pages, LaTeX, no macros needed


26. hep-ph/9405372 [abs, ps, pdf, other] :
Title: An Automatic Invisible Axion In The SUSY Preon Model
Authors: K.S. Babu, Kiwoon Choi, J.C. Pati, X. Zhang
Comments: (TeX file) 16 Pages
Journal-ref: Phys.Lett. B333 (1994) 364-371


27. hep-ph/9212275 [abs, ps, pdf, other] :
Title: Light fermions in composite models
Authors: S. Yu. Khlebnikov, R. D. Peccei
Comments: 22 pages, 2 figures not included, latex, UCLA/92/TEP/49
Journal-ref: Phys.Rev. D48 (1993) 361-369


28. hep-ph/9211288 [abs, ps, pdf, other] :
Title: Flavor Changing Neutral Currents in a Realistic Composite Technicolor Model
Authors: Christopher D. Carone, Rowan T. Hamilton (Lyman Laboratory of Physics, Harvard University, Cambridge, MA 02138)
Comments: 16 pages, LaTeX + embedded PicTeX figures requiring prepictex, pictex, and postpictex inputs. HUTP.STY included
Journal-ref: Phys. Lett. B301 (1993) 196-202

 

[ohwilleke]

Date: Tue, 22 Mar 2005 08:48:11 GMT (52kb)
http://es.arxiv.org/abs/hep-ph/0503213

A topological model of composite preons
Authors: Sundance O.Bilson-Thompson
Comments: 9 pages, 3 figures, submitted to Phys. Lett. B
Report-no: ADP-05-05/T615

We present a modification of the preon model proposed independently by Shupe and Harari. A basic dynamics is developed by treating the binding of preons as topological in nature and identifying the substructure of quarks, leptons and gauge bosons with elements of the braid group B_3. Topological considerations and a straightforward set of assumptions lead directly to behaviour consistent with much of the known phenomenology of the Standard Model. The preons of this model may be viewed as composite in nature, and composed of sub-preons, representing exactly two levels of substructure within quarks and leptons.

Description

This is a clean version of Harari's approach.

It proposed that two basic types of particles (basically, half loops) called U and E can combine in types UU, EE, or EU=UE. The pairs are called Helons which in turn are labeled H+, H- and Ho (I will omit the H's and just show the signs and use upper and lower case to denote particles and anti-particles)

Helons form into either braided or unbraided triplets, which cannot contain both a + and a - at the same time. Braided triplets corrospond to fermions by the following formula:

First Generation Leptons:
Positron=+++
Electron=---
Neutrino=000
First Generation Quarks
Blue U=++0
Blue d=00+
Blue u=--0
Blue D=00-
Red U=+0+
Red d=0+0
Red u=-0-
Red D=0-0
Green U=0++
Green d=+00
Green u=0--
Green D=-00

All fermions can be either right or left handed. The neutrino is its own antiparticle but still has handiness (right or left).

Bosons
These are unbraided triplets:
W+=+++
W-= ---
Photon is three untwisted 000s (i.e. neither right nor left)
Zo is three countertwists 000s (i.e. both right and left)

Mass
Mass is not precisely spelled out (reserved for future publications ), but it is a product of aggregate twistiness and possibly also charge. Thus, a photon, which is completely untwisted, is massless, while twisted charged particles are more massive.

Second and further generation particles are not spelled out, but proposed basically to have additional twists beyond those absolutely necessary to create their characteristics.

QCD Color
QCD color effects are explained by the requirement that baryons be viewed as stacks of quarks and that each set of three subcomponents must have the same aggregate charge helon charge.

Comment:

This has the virtue of creating a model that closely maps to the standard model in charge, color, and parity constraints, and establishing the experimentally discovered number of particles without excess or shortage (although it isn't clear how this model of the photon handles the varied properties of a photon like polarization and frequency) with a great deal of simplicity.

It fails, however, in this iteration to explain particle masses, and it is hard to see how so simple a set of triplets could produce the complex mass structures which actually exist.

 

[ohwilleke]

Note that Yershov, Friedriksson, and Bilsom-Thompson all "independently" come to the conclusion that the level of structure immediately below the standard model must have multiple types of components (Yershov says three colors of Ys with antiparticles, Fredriksson with three kinds of particles with antiparticles, while Bilsom-Thompson uses onlyt H+, Ho and H- with no antiparticles), although both Yershov and Bilsom-Thompson note that this fairly simple typology can be derived by one more level of an even simpler structure (three kinds of preons in Yershov's case, two kinds of tweedles in Bilsom-Thompson's case).

None of Yershov's conclusions require anything more fundamental than the Y particles he proposes, and none of Bilsom-Thompson's conclusions require anything more fundamental than the Helons. The strong indication is that neither preons (or preon doublets) nor tweedles could be experimentally discovered, and that even Yershov's Y-particles and Bilsom-Thompson's Helons would be confined at all times.

But, Yershov's success with the mass problem suggests that he is closer to the right track in terms of particle structure (although, while he claims that there are no free parameters in his theory, in fact, the theory hardly necessitates the particle structures he proposes in the absence of data).

Fredriksson's approach seems, at face value, the lease compellling of the three. Unlike Yershov's approach it does not explain particle mass, and it doesn't seem as transparent.

Fredriksson's approach predicts a fourth generation of particles (the Kappa Electron, Kappa Neutrino, H quark, G quark, another heavy neutrino, a possibly unphysical X quark, 4 new Zs and 2 new Ws).

Bilsom-Thompson's approach could produce additional generations beyond the three that we observe, at least among fermions, without apparent limit. But, each particle appears as if it should fit in a generation.

Yershov's approach also predicts large numbers of extremely short lived or confined particles such as the Y*, Y**, Y***, two preon doublets, and two types of heavy neutrinos. It is also not at all obvious that his set of possible particles is complete, although his topological approach makes not all combinations of particles physically possible, and appears at first glance to dispense with the need for a Higgs boson.

 

[ohwilleke]

Various Google Search Results:

Physics Essay volume 10, number 1, 1997, "The A-B-C Preon Model" by D.J. Larson
http://www.dipmat.unipg.it/~bartocci/fis/larson2.htm

"James N. Bellinger, author
Atoms are made of a nucleus and electrons; nuclei are made of protons and neutrons, and these are made of quarks and gluons. We can ask if the quarks (and electrons) are themselves made of something even smaller, which we usually call preons [pree-on]." http://www.hep.wisc.edu/~jnb/poster_group/posterbig.html

Wikipedia (mostly by yours truly): http://en.wikipedia.org/wiki/Preon

 

[ohwilleke]

More links:

Lubos Motl on Preons (IMHO making tearing down strawman arguments, rather than fairly addressing the possibility): http://www.lns.cornell.edu/spr/2001-09/msg0035261.html

From: Sverker Fredriksson [view email]
Date: Wed, 3 Sep 1997 10:52:21 GMT (12kb)
Date (revised): Mon, 29 Sep 1997 14:47:02 GMT
Date (revised): Tue, 4 Nov 1997 16:30:13 GMT
http://arxiv.org/abs/hep-ph/9709227
Higgs Pain? Take a Preon!
Authors: J.-J. Dugne, S. Fredriksson, J. Hansson, E. Predazzi
Comments: The preon contents of some quarks and leptons have been changed in order to achieve a more consistent scheme. A few new comments have been added. 13 pages, LaTeX, no figures. To be published in Proc. of the Meeting on 'The Fundamental Structure of Matter' and 'Tests of the Electroweak Symmetry Breaking', Ouranoupolis, Greece, May 1997

The Higgs mechanism is the favourite cure for the main problem with electroweak unification, namely how to reconcile a gauge theory with the need for massive gauge bosons. This problem does not exist in preon models for quark and lepton substructure with composite $Z^0$ and $W$s, which, consequently, also avoid all other theoretical complications and paradoxes with the Higgs mechanism. We present a new, minimal preon model, which explains the family structure, and predicts several new, heavy quarks, leptons and vector bosons. Our preons obey a phenomenological supersymmetry, but without so-called squarks and sleptons, since this SUSY is effective only on the composite scale.

 

[ohwilleke]

Jongbae Kim 1998 J. Phys. G: Nucl. Part. Phys. 24 1881-1902
http://www.iop.org/EJ/abstract/0954-3899/24/10/006

Explanation of the masses of quarks and leptons in a supersymmetric preon model
Jongbae Kim
Department of Physics, University of Maryland, College Park, MD 20742, USA
and
Research Department, ETRI, Yusong PO Box 106, Taejon 305-600, South Korea
Received 8 December 1997
Print publication: Issue 10 (October 1998)

Abstract. We have studied whether the radiative effects including gauge and Yukawa interaction corrections can improve the phenomenological consequences on the masses of quarks and leptons in the supersymmetric preon model. Our study shows that pure renormalization effects in the region from the metacolour scale to the electroweak scale produce quark-lepton distinction within a given family. They cannot, however, produce the desired up-down distinction or the expected quark-lepton asymmetry in the effective hierarchy parameter of the up, down and lepton sectors. It also shows that the pure radiative corrections cannot explain the `fine structure' effects exhibited by . These lead us to conclude that the symmetry structure of the preon theory cannot strictly respect left-right, up-down and quark-lepton symmetries near and below the Planck scale. This subsequently implies the symmetry both as regards unification of couplings near the Planck scale in the model and as regards its possible origin from a superstring theory.

 

[ohwilleke]

From: Ruben Mkrtchyan [view email]
Date: Fri, 8 Aug 2003 17:56:01 GMT (10kb)
http://arxiv.org/abs/hep-th/0308065

Little Groups of Preon Branes
Authors: H.Mkrtchyan, R.Mkrtchyan
Comments: LaTeX, 11 pages
Journal-ref: Mod.Phys.Lett. A18 (2003) 2665-2672

Little groups for preon branes (i.e. configurations of branes with maximal (n-1)/n fraction of survived supersymmetry) for dimensions d=2,3,...,11 are calculated for all massless, and partially for massive orbits. For massless orbits little groups are semidirect product of d-2 translational group $T_{d-2}$ on a subgroup of (SO(d-2) $\times$ R-invariance) group. E.g. at d=9 the subgroup is exceptional $G_2$ group. It is also argued, that 11d Majorana spinor invariants, which distinguish orbits, are actually invariant under d=2+10 Lorentz group. Possible applications of these results include construction of field theories in generalized space-times with brane charges coordinates, different problems of group's representations decompositions, spin-statistics issues.

Fermilab Mass Paradox issues: http://www.npl.washington.edu/AV/altvw80.html

Three-preon models of quarks and leptons and the generation problem
Y. Tosa and R. E. Marshak
http://prola.aps.org/abstract/PRD/v27/i3/p616_1
Department of Physics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061

Received 27 August 1982
We have carried out a search for three-fermion preon models that predict at least three generations of quarks and leptons. The conditions imposed are the following: (1) The preons are (massless) Weyl spinors and belong to low-dimensional chiral representations of the gauged symmetry group G(MC) x G(CF), where MC stands for metacolor and CF for color-flavor. (2) G(MC) is an asymptotically free simple group while G(CF) is a grand-unification-theory (GUT) or partial-unification-theory (PUT) group. (3) The Pauli principle holds when generalized to the MC degree of freedom. (4) No anomalies exist in the MC and CF sectors. (5) The composite quarks and leptons are massless on the MC scale. (6) There are no low-representation exotics and no mirror fermions. The only GUT preon models satisfying these six conditions are SU(3)(MC) x SO(10)(CF) with four generations and F4(MC) x SO(10)(CF) with three generations; however, asymptotic freedom is marginal for the two GUT models. The only permissible PUT preon model is E6(MC) x SU(4)C x SU(2)L x SU(2)R with three generations, and satisfactory asymptotic behavior. The PUT preon model is therefore the most promising and further implications are discussed.

Power point on Why Quarks Cannot Be Fundamental Particles:
capp.iit.edu/beach04/talks/kalman.ppt

The cosmological consequences of the preon structure of matter
Vladimir V. Burdyuzha,1 Grigory M. Vereshkov,2 Olga D. Lalakulich,2 and Yuri N. Ponomarev1
1Astro Space Center of Lebedev Physical Institute of Russian Academy of Sciences, Profsouznaya str. 84/32, 117810 Moscow, Russia
2Rostov State University, Stachki str. 194, 344104 Rostov on Don, Russia
http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=APCPCS000478000001000392000001&idtype=cvips&gifs=yes

If the preon structure of quarks, leptons and gauge bosons will be proved then in the Universe during a relativistic phase transition the production of nonperturbative preon condensates has occurred. Familons are collective excitations of these condensates. It is shown that the dark matter consisting of familon type pseudogoldstone bosons was undergone to two relativistic phase transitions temperatures of which were different. In the result of these phase transitions the structurization of dark matter and therefore the baryon subsystem had taken place. In the Universe two characteristic scales which have printed this phenomenon arise naturally. ©1999 American Institute of Physics.

 

[arivero]

Uff! Espectacular review. Let me humbly add the Search Report
http://pdg.lbl.gov/2004/reviews/quarklep_s054.pdf

 

[arivero]

28. hep-ph/9211288 [abs, ps, pdf, other] :
Title: Flavor Changing Neutral Currents in a Realistic Composite Technicolor Model

For a lot of time, I had though that Technicolor and preons were one and the same research line. I would like to blame to this kind of titles, instead of acknowledging my own lack of familiarity with the field. But on other hand the buzzwords "composite technicolor" were used time ago by the Mallinckrodt chair, in http://dx.doi.org/10.1016/0550-3213(87)90638-9 and
http://prola.aps.org/abstract/PRD/v36/i7/p2102_1.

 

[Haelfix]

The problem with preon models is always the same thing. Namely, you have to match T'Hooft Anomaly conditions exactly, and control fcncs to observed levels, and this severely constrains the possible phenomological models you can write down.

When you add SUSY to the mix, afaik its nearly impossible as you end up with badly divergent helicity violating terms.

 

[ohwilleke]

SUSY is well on its way to the toilet of physics history. It simply predicts too many supersymmetric partners that the evidence does not support the existence of. It is a classic example of the looks pretty, but doesn't work fad in modern physics. Preon theory is, if anything, primarily a solid argument for why SUSY particles should not exist and are not necessary.

Also, constraints are not necessarily a bad thing. You need just one phenomological model to work and you'd like to have it be unique.

 

[arivero]

Yershov (March 2003):
...

Predicted Mass (preon units;mass of proton=1 units) Experiment
electron=9 preon units; 0.0005446175 mp; 0.0005446170232(12) mp
u quark=78 preon units; 0.004720019 mp; 0.0047 mp
d quark=123 preon units; 0.007443106 mp; 0.0074 mp
...

Too many arbitrary choosing in the preon structure. Surely it does not survive GIGO (Garbage In, Garbage Out) tests. A paper cited by Yeshov, physics/0109024, has the same problem (pages 44 and 45).

 

[arivero]

SUSY is well on its way to the toilet of physics history. It simply predicts too many supersymmetric partners that the evidence does not support the existence of.

Still, model builders keep trying. Here is one 1997 susy preon (superpreons?) model from Nima: http://arxiv.org/abs/hep-ph/9712389

 

[Haelfix]

That paper by Nima is not really a realistic model, but more an early attempt at solving the susy breaking problem. The gauge embedding used would lead to serious theoretical problems (landau poles near the composite scale) not to mention being ugly.

It also breaks perturbative unification and I suspect there is problems with the usual triangle and striangle anomaly matching conditions (but I may be wrong on that).

However it does illustrate some of the problems of field theory. when you embed the standard model into some larger gauge group (say SU(N) where N --> infinity), the cat is out of the bag so to speak. There is usually a few choices (eg complicated) representations whereby you can push problems to higher and higher scales somewhat arbitrarily.

 

[ohwilleke]

Several Preon papers at a 1986 physics conference are found here:
http://www.phys.vt.edu/~ippap/publications/hep86.html

and 1985 here:
http://www.phys.vt.edu/~ippap/publications/hep85.html

 

[ohwilleke]

A paper on Binons by our own Carl B:

http://www.brannenworks.com/PHENO2005.pdf

 

[arivero]

I hope CarlB will get time to comment a bit more on his work here, as well as the reactions in the PHENO2005 meeting.

 

[Hans de Vries]

I hope CarlB will get time to comment a bit more on his work here, as well as the reactions in the PHENO2005 meeting.

Carl is a bit reluctant to discuss his paper here. I don't think that it should
be a problem since he was invited to do so here.

The discussion in his paper on the deBroglie wave and Special Relativity
and his doubts prompted me to finalize a short note on the:

"Relativistic kinematics of the wave packet"

http://www.chip-architect.com/physics/deBroglie.pdf

Which sheds light on some of the beautiful relations between SR and QM
like the phase speed and the group speed of the deBroglie wave. As with
most things: It's all very logical once properly understood.


Regards, Hans.

 

[CarlB]

Hans, it's not so much that I'm reluctant, but that I don't want to post where I'm not wanted. For the moment, I'm busily typing up a second paper, one that delves much deeper into quantum mechanics.

I found your paper interesting. The de Broglie observation that the phase velocity of matter waves are generally > c can be interpreted in other ways.

For example, the phase velocity of matter waves drops to c if the matter moves at the speed of light. This can be considered an argument that, for example, the electron should be considered as the combination of two massless chiral particles, that is, an $$e_L$$ and an $$e_R$$ coupled by the force responsible for mass.

Another interpretation of the superluminal phase velocities is that there must be a hidden dimension where the phase velocities are c. My paper makes both assumptions.

I don't recall seeing any other explanations for the superluminal speed of phase velocity other than, as in the Wizard of Oz, "don't look behind that curtain". The point here is that the above gives two ways to allow the interpretation of matter waves as waves through a media.

Carl

 

[CarlB]

It doesn't look like I'll finish the paper that deals with the mass formula until several weeks from now. So I thought I'd give a little hint as to what is going on in the theory.

The heart of my method is to represent the particles with idempotents instead of spinors. Towards that end, I thought I'd share with the thread a calculation for the Stern-Gerlach experiment with an angle of $$\theta$$ between consecutive measurements but using idempotents instead of spinors. For the Clifford algebra, we will use the Pauli spin matrices.

Represent a spin-1/2 particle oriented in the $$\hat{u}$$ direction by an idempotent matrix:

$$|+u \rangle \equiv (1 + u_x\sigma_x + u_y\sigma_y + u_z\sigma_z)/2.$$

A particle oriented in the +z direction is therefore represented by the idempotent:

$$(1 + \sigma_z)/2$$

To compute the transition probability for the +z particle with a particle oriented in the +u direction (i.e. the probability of measurement as +1/2 in the second Stern-Gerlach apparatus), simply compute twice the scalar part of the product. In Clifford aglebra notation, this is:

$$P_{++} = 2\langle(1 + \sigma_z)/2 (1 + u_x\sigma_x + u_y\sigma_y + u_z\sigma_z)/2 \rangle_0$$
$$= (1 + u_z)/2 = (1 + \cos(\theta))/2$$

Thus the transition probability is just twice the scalar part of the product. This works for arbitrary idempotent spin matrices. The factor of two comes from the trace of the identity matrix. That is, you can write "tr(AB)" instead of "2<AB>_0".

Note that the method of calculation is considerably simpler than that using spinors, which requires an inner product (which requires a complex conjugation and transposition), a squaring, and a magnitude. In addition, the representations of spin in a given direction are determined by simple vectors, so there is no need to fish around for solutions to eigenvalue problems to find the eigenvectors.

The calculation is clean and coordinate free. One clear disadvantage is that it allows a stupider class of student to find models of particles with a given spin orientation and to compute transition probabilities, but alas, a more fundamental theory should be associated with simpler calculations.

This suggests that idempotents are a very natural way of representing spin-1/2, and by extension, isospin and other features of elementary particles, which is what my papers are all about.

Carl

 

[ohwilleke]

The calculation is clean and coordinate free. One clear disadvantage is that it allows a stupider class of student to find models of particles with a given spin orientation and to compute transition probabilities, but alas, a more fundamental theory should be associated with simpler calculations.

The committee for the perpetuation of the physicist job security will be contacting you in the near future.

 

[CarlB]

On the subject of using idempotents to represent particle states, rather than spinors, I should mention that this is an application of J. Schwinger's "Measurement Algebra" to the problem of the Stern-Gerlach apparatus for spin-1/2 particles.

Schwinger wrote a book deriving QFT in an unusual manner: "Quantum Kinematics and Dyanmics" (1969). It's been reprinted by Perseus in the ABP "Advanced Book Classics" series and is available at Amazon.com for $17.49:


It is possible to read the book without appreciating the fact that in it, probabilities are proportional to inner products, rather than the squares of inner products. I don't know why he didn't make it more obvious.

In section 1.6, "The Statistical Interpretation", Schwinger computes the probability of a particle going through three Stern-Gerlach apparata with orientations A, B, A, as compared to a particle going through a single Stern-Gerlach apparatus with orientation A. From the outside, the only difference you can tell between the two experiments, ABA versus A, is that in the ABA case, fewer particles come out the end. He calculates the probability as:

$$p(a',b') = |<a'|b'>|^2\;\; (1.41)$$

But the square here is only due to the fact that he is modeling a transformation from A to B and then back to A. From the point of view of the usual Stern-Gerlach calculation, the probability of surviving the transition from A to B is the same as from B to A (by symmetry), so each of these transition probabilities is given by the square root of the above:

$$p = |<a'|b'>|$$

Thus in the Schwinger measurement algebra, as with the idempotents I favor, probabilities are proportional to inner products and not squares of inner products.

By the way, Schwinger doesn't use the phrase "primitive idempotent". Instead, he calls the things he works with "elementary selective measurements". But if you examine the algebraic relations he uses in sections 1.1-1.5, it is clear that "primitive idempotents" are what the mathematicians (or Clifford algebraists) would call it.

As it turns out, Amazon has been so kind as to allow readers to read the first chapter of the book (click the "excerpt" link on the Amazon website linked in above). This turns out to contain all the references I've included above.

So if you want to learn the basics of the Schwinger measurement algebra, which is very rarely mentioned in modern quantum mechanics, you can learn the basics very quickly and for free.

Considering that Schwinger wrote a whole book on the subject, and that it allows computation of Stern-Gerlach experiments without all the eigenvector difficulties, it is rather amazing that I could find only a single paper on Arxiv.org that uses it:

http://arxiv.org/abs/hep-th/9702080

well maybe this one too, though he doesn't reference "schwinger":
http://arxiv.org/abs/quant-ph/0203105

Carl

[edit] Per Kea's note just after this one to the effect that the first of the two arxiv links (just above) is about a quaternionic generalization to the Schwinger measurement algebra, I should mention that quaternions show up in Clifford algebras.

If you wish to map the elements of a Clifford algebra over to a set of square matrices (whose multiplication and addition will match the CA), then you have to assume that the square matrices take values from either the reals, the complexes or the quaternions, depending on which CA you are using. There are tables showing the correct choice in any CA textbook.

From my own point of view, I prefer to keep all the matrices complex (or real). If I want to deal with a CA that would require quaternions in order to be put into square matrices, I will simply double the size of the matrices (from being 2^n square to being 2^(n+1) square matrices), and keep in mind that the Clifford algebra will not include all such square matrices.

To do this, simply add one more canonical basis vector to your CA. This will eliminate the need for the quaternions. Now get the isomorphism from this new CA to square matrices (over the reals or complexes), but ignore the canonical basis vector that you added. Because you're ignoring a canonical basis vector, you won't be able to get all the possible square matrices. Instead, you'll be working in a subalgebra of the square matrices.

That way I don't have to deal with quaternions.[/edit]

 

[Kea]

Carl

This is great. I wasn't aware of the Schwinger reference. Unfortunately my library doesn't have a copy. For those interested, http://arxiv.org/abs/hep-th/9702080 is about quaternionic QM.

Cheers
Kea

 

[Kea]

Hi ohwilleke

A topological model of composite preons
Sundance O.Bilson-Thompson
9 pages, 3 figures, submitted to Phys. Lett. B

"We present a modification of the preon model proposed independently by Shupe and Harari."

It proposed that two basic types of particles (basically, half loops) called U and E can combine in types UU, EE, or EU=UE ...

I just spotted your post. Interestingly, Harari has coauthored with Seiberg.

Note that the basic 'particles' of Bilson-Thompson (tweedles) are actually pieces of twisted ribbons, coming in three flavours corresponding to twists of $\theta \in + 2 \pi , - 2 \pi, 0$ describing charges of $q = \frac{e \theta}{6 \pi}$.

Cheers
Kea

 

[Hans de Vries]

it is rather amazing that I could find only a single paper on Arxiv.org that uses it:

Amazon unfortunately gives me only the first 6 pages. I did found some
more on Schwinger's measurement algebra here:

http://kevin.phys.unm.edu/~kevin/meas_alg.pdf

Regards, Hans

 

[arivero]

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.

 

[CarlB]

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

 

[ohwilleke]

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.

 

[arivero]

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!

 

[Antiphon]

They should haved called the preon a "turtle" and killed two birds with one stone.