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

[gurkhawarhorse]

thats right

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

thats right!

 

[arivero]

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

Now I get it But indeed it could be also that the quarks themselves are the turtles, the hadrons being the elephants.

 

[arivero]

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 (

 

[marcus]

maybe we should keep this thread handy as a resource

it looks like ohwilleke and others put some work into researching it

thx especially for this
https://www.physicsforums.com/showpost.php?p=581108&postcount=7

 

[Rade]

A new preon model:
http://www.geocities.com/ptep_online/PP-04-04.PDF
found in this journal:
http://www.geocities.com/ptep_online/2006.html

 

[arivero]

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 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.

 

[ChrisMelani]

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.

 

[CarlB]

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

 

[arivero]

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

 

[arivero]

Sundance preons have now a specific thread:
https://www.physicsforums.com/showthread.php?t=113185

 

[arivero]

CarlB, any news of the Sunday meeting? Nice people to recruit for Physics Forums, at least?

 

[arivero]

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

 

[CarlB]

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

 

[arivero]

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).

 

[CarlB]

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

 

[arivero]

Ernest Ma in hep-ph/0606039 does a toast to preons when reviewing tribimaximal mixing, he says:

Notice that the 3 vertical columns are evocative of the mesons $$\eta_8, \eta_1, \pi^0$$ in their SU(3) decompositions.

 

[arivero]

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
$$\sqrt { m_1 m_\tau} =^? \sqrt{m_2 m_\mu}+\sqrt{m_3 m_e}$$

 

[CarlB]

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

 

[arivero]

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
$${-\sqrt{m_1} + \sqrt{m_2} +\sqrt{m_3} \over \sqrt{m_1+m_2+m_3} \sqrt{3}} = {1 \over \sqrt 2}$$becomes
$$\sqrt{m_2} (1-\sqrt{ m_\mu\over m_\tau})+\sqrt{m_3} (1-\sqrt{m_e\over m_\tau}) = \sqrt \frac 3 2 \sqrt{ m_2 (1+{ m_\mu\over m_\tau}) + m_3 (1+{m_e\over m_\tau}) + \sqrt{ 2 m_2 m_3 { m_\mu m_e \over m_\tau^2} }}$$

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

$$.75615 \sqrt{m_2\over m_3} + .983042 =\sqrt \frac 3 2 \sqrt{1.059459 {m_2\over m_3} + 1.00028756 + .0116954 \sqrt{ m_2 \over m_3} }$$
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

 

[Kea]

Hey, folks! Sundance preons are no longer fringe. Check out the cover of the August 12 New Scientist.

 

[selfAdjoint]

Hey, folks! Sundance preons are no longer fringe. Check out the cover of the August 12 New Scientist.

Are you sure that being on the cover of New Scientist counts as non-fringe evidence?

 

[Kea]

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.

 

[arivero]

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

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.

 

[arivero]

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.

 

[arivero]

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...

 

[arivero]

It is not rare to see the mass of the pion as proportional to the square root of the mass of the constituyent quark. I have just seen it in a old work by Olivier Martin. Hmm.

Ah, another funny reference for the preon thread. Peskin 1981 is scanned in KEK:
http://ccdb4fs.kek.jp/cgi-bin/img_index?8202032 Enjoy!

 

[CarlB]

Nice link. "For theorists, my requests are more serious: ... The third, and most pressing, is to learn how to compute the mass spectrum of quarks and leptons in composite models, even in models too simple to be realistic. It is, after all, only through the computation of the quark and lepton masses that the idea of compositeness can really fulfill its promise."

 

[arivero]

Hmm Zee preons are not mentioned in this thread, are there?
http://es.arxiv.org/abs/hep-ph/0508278
http://es.arxiv.org/abs/hep-ph/0604169

 

[CarlB]

Hmm Zee preons are not mentioned in this thread, are there?
http://es.arxiv.org/abs/hep-ph/0508278
http://es.arxiv.org/abs/hep-ph/0604169

Hmm. Tetrahedral group? I wonder where that would come from. See figure 6.4 on page 93(107):
http://www.brannenworks.com/dmaa.pdf

 

[arivero]

See figure 6.4 on page 93(107):

It seems a different context, but I have not traveled across your whole work

In any case, it is sort of consolation to see that people in the academy as Zee and Ma are keeping these topics live.

On my own side, I do not see how to fit A4 in my susypreonic model.

 

[arivero]

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

I have just noticed Adler's preons in the final chapter of his book on quaternionic quantum mechanics. He generalises Harari model by allowing two different permutations; one for T/V and another for spin +/-. In his generalisation, the three generations come from the three differents ways of ordering ++- +-+ -++ the spins, in the same way that the three colours come from TTV TVT TTV.

 

[tehno]

hart

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.

At what threshold energies are the quark "preons" expected to be detected in a proton collider experiments?

 

[arivero]

Carl, now that your cliffordian cube is hung, very appropiate, in Clifford's site, I think you should pair a visit to the old articles of Wilczek and Zee and include the quotation in your http://brannenworks.com/PHENO2005.pdf

I refer to "Families from Spinors",
http://prola.aps.org/abstract/PRD/v25/i2/p553_1
As far as I can find, the earliest use five clifford algebra generators to build the fermions appears in the body of this article (and some extra hints in the appendix). If you know of earlier work, please tell me!

Actually I think I understand how it happens, and that really we need to take six generators to build both the fermions and their susy partners, in this way it is a 6-dimensional algebra and it explains why the "Newton Institute Spectral Triple" (as I hve christened it, to differ from "Les Houches Spectral Triple") is 6-dimensional.

 

[arivero]

Ah, another funny reference for the preon thread. Peskin 1981 is scanned in KEK:
http://ccdb4fs.kek.jp/cgi-bin/img_index?8202032 Enjoy!

I have rescued Peskin's note. It is actually very interesting to check page 3. His description of models of the second kind hints why such models are forcefully related to spin and then to Clifford algebras. He does not point towards Wilczek and Zee papers, probably because they are contemporary, but the explanation in W & Z follows similar trends.

All together, the paper is a hint about why Clifford modelers in the internet are not considered in the mainstream: the mainstream tried these tricks in the late seventies and failed.

Hmm Zee preons are not mentioned in this thread, are there?
http://es.arxiv.org/abs/hep-ph/0508278
http://es.arxiv.org/abs/hep-ph/0604169

Amusingly, the papers quote as main paper http://www.slac.stanford.edu/spires/find/hep/www?irn=310417

I have just noticed Adler's preons in the final chapter of his book on quaternionic quantum mechanics. He generalises Harari model by allowing two different permutations; one for T/V and another for spin +/-. In his generalisation, the three generations come from the three differents ways of ordering ++- +-+ -++ the spins, in the same way that the three colours come from TTV TVT TTV.

http://arxiv.org/abs/hep-th/9610190 and http://arxiv.org/abs/hep-ph/0201009 are claimed to be follow-ups.

 

[arivero]

Still, the class b models group up to five SU(2) labeled particles because they need to produce a fermion. I like more my approach of getting composite bosons and elementary fermions. This is because my model predicts both the number of generations and the number of top quarks.Consider N families with q interacting up quarks and p interacting down quarks. We have the obvious constraing 0 =<p=<N, 0 =<p=<N. If we ask for a matching of degrees of freedom, consider that for a given charged fermion we have 2 N degrees of freedom. Supersymmetry between composites and elementary particles requires the following equations:
p*q = 2N (for u+d) and p*(p+1)/2 = 2N for (d+d). From the second one we have
that the number of generations must be such that (1 + 16 N) is a perfect square and N>=p >= (-1+sqrt (1+16N))/2, so that N>=3. The lowest possibility is N=3. Then p=3 and q=2: we have 3 light downĺike quarks and two light uplike ones.

(ok, what about N=5 (fails because p=4, but q=2.5) or N=14 (ok with p=7, q=4) and so on? The point is that the union of up+antiup and down+antidown should also sum the number of degrees of freedom of the neutrinos, the providing a further constraint, still to be researched)