[SOLVED] living without CERN

[Erdem]

do you think that without CERN particle physics can not progress?

create your own accelerator!!!!

[selfAdjoint]

Why am I sure you're going to tell us how?

[1100f]

Originally posted by selfAdjoint
Why am I sure you're going to tell us how?

That's easy.
Go to the bank, ask for a loan of a few billions of dollars.
If the bank gives you the loan, than you can build your own particle accelerator and give up CERN.
If you don't get the loan, well, you still have to rely on CERN, SLAC, etc.

I'll try this tomorrow and let you know.

[fudge]

Sorry, I've got to ask... do you guys think the Higgs will ever be found?

3 years sure does seem like a long time :(

[fudge]

Originally posted by 1100f
That's easy.
Go to the bank, ask for a loan of a few billions of dollars.
If the bank gives you the loan, than you can build your own particle accelerator and give up CERN.
If you don't get the loan, well, you still have to rely on CERN, SLAC, etc.

I'll try this tomorrow and let you know.

How do you propose to get such a huge loan? And why would 'relying' on cern be soo bad??

[1100f]

Originally posted by fudge
How do you propose to get such a huge loan? And why would 'relying' on cern be soo bad??

My answer was a little sarcastic and was intended to the original poster who underestimated the work done at CERN and suggested to build an accelerator.
As I don't believe that I could get such a huge loan, I think that relying on CERN, SLAC etc. is the only thing left.

And in no way I intended to say that relying on CERN is bad. Although my personal taste is for theoretical physics, and the standard model is one of the most beautiful model, it is useless without the experimental results.

[mormonator_rm]

CERN, KEK, Fermilab, SLAC, DESY, Brookhaven, VEPP,... there's all sorts of accelerator labs to rely on!

Last I heard (a year or two ago) the Higgs particle was found at CERN in electron-positron annihilation spectra just a few weeks before they were going to close down the LEP ring permanently. I thought somebody else confirmed it later, too.

The SSC was going to cost over ten billion, and they just about had the money in hand. Government decided against it during that budget crisis back in '94, took all the funding back!

[selfAdjoint]

I think that CERN's tentative Higgs discover was later withdrawn. The cranks crowed loudly at the time "See! Quantum Physics doesn't work!". Bad cess to them.

[mormonator_rm]

That stinks. Somehow I missed that. I went and checked Phys. Rev. and sure enough they still just show limits. But the limit found at LEP by Heister et al. is highlighted by the PDG as their best limit. It places H~0 above 89.8 GeV, and the pseudoscalar A~0 above 90.1 GeV (in the supersymmetric model). The combined direct results from the LEP came to > 114.4 GeV, which is highlighted by PDG. They were looking at events generated from > 209 GeV; if Higgs is out there, and doesn't fall in the distribution they checked, then its going to be holey freakin' massive! Bigger than the top quark, for goodness' sake!

[arivero]

The ALEPH experiment got a 3 standard-deviations signal, but the other experiments either did not show signal or got it near background. So the average is good enough for a lower bound, but it does not amount to discovery. It should be noted that the machine was running, in some sense, beyond the end of its engineering goals.

The ALEPH plot is
http://lephiggs.web.cern.ch/LEPHIGGS/papers/LEP-SM-HIGGS-PAPER/fig8a.eps
at the CERN website
http://lephiggs.web.cern.ch/LEPHIGGS/www/Welcome.html

The final paper is going to appear in Phys.Lett.B. and it is very conservative.

By the way, last week my own "higgs discovery theory" was moved to Theory Development, http://www.physicsforums.com/showthread.php?s=&threadid=9716
I speculated if it was possible to get Higgs signatures from pure low energy nuclear data. You can check the corresponding paper in the ArXiV, http://arxiv.org/abs/nucl-th/0312003

[mormonator_rm]

Arivero, I went and read your paper, and in particular I found the data around the top mass to be interesting, especially from the first graph. Also the note on f0(600). My own work deals with identifying the ground state scalar glueball in ppbar annihilation data, and hence the scalar mesons and nucleons are of great importance to me. I finished some work on the Monte Carlo program to be used in the attempt, and published it in the Proceedings of NCUR 2003. The more I look back at my article, the more I realize it comes across as being very naive, so I won't refer you to it; I find it embarrasingly simplistic and watered down as well.

I don't know if this is a good place in which to discuss your work with you, so I won't ask any questions right now.

[arivero]

Hi mormonator_rm,

Yep I saw your reply on the sigma. I am printing it to digest it at home!

About discussing here, well, it is a places as good as any other, and the theme is On Topic (as the Higgs is an scalar, too, and the plot is genuine "living without CERN"). Besides, I need to pulish it towards refeering, because my background is MathPhys, not nucleal.

Now, I believe there is no much meat in the first plot, as most of it comes from the neutron magic numbers, so the second one is more relevant to look at the issue.

Which your ideas about the top mass were?

[mormonator_rm]

I'm sorry, I meant the second graph. I completely forgot about the first one. I was noticing the three magic numbers that occured at higher energies. In particular, the one closest to Z mass was fairly close, the one closest to H mass was also somewhat close (understanding that the H mass is not actually determined), but the one nearest to top mass appears to correspond to about 5 or 10 GeV above top mass, still a fair distance off. I was just thinking about what object may have a mass closer to that, and still involving a top quark, perhaps a meson with both topness and bottom. I wonder if perhaps there is a greater contribution from mesons with both topness and bottom due to the possibility that mesons composed of a top quark and a lighter quark would have a greater tendency to change the quark content of a nucleon, rather than just mediate (prescence of up or down quarks/antiquarks could result in conversion of protons to neutrons or the reverse?). I hope this makes some sense.

[arivero]

Yup, the first one is completely trivial, so it is easy to forget. I'll remove it in the final version.

I agree with you, a top/bottom combination, 5GeV away from the line, seems a better fit, it was just that I was not unable to justify why a top/antibottom meson was better that, say, a top/antidown. Still, your justification does not preclude stangeness or charm :-(

Really it is not important to be exactly at the magic number, because there is nothing to justify there. The scent to follow is the subshell which completes the magic number. At highest numbers, it happens that the subshell is bigger (12 or 14 nucleons), so the line scales nicely away the doubly magic atom.

By the way, I am learning a lot about the sigma. It seems that current practicioners see it as a trick to implement two-pions exchange, but there do not believe on it anymore.

To me, such belief is a positive thing, as I only need to balance a single, but weak force, coupling (higgs etc) against a double, and residual force, exchange.

[mormonator_rm]

Might preclude strangeness on the grounds that hypernucleii are not involved. Also, the strange quark mass mixes very well with the lighter quark masses. Charmness could bring it a couple GeV closer, but bottomness would give the best fit, indeed.

Well, if sigma is anything like the f0(980), it may well be a pion-pion bound state, probably in S-wave. This could be the very trick needed to implement the exchange. Besides, I have read that sigma meson may be the chiral partner to the pion. That brings up another interesting observation on the light scalars I might mention; if you think about it, f0(980) is just slightly more massive than the eta' meson (957.78 MeV) in the pseudoscalar group, and if sigma is the same as f0(600), then it is only somewhat more massive than the eta meson (547.30 MeV). This basically says that f0(980) and f0(600) i.e. sigma are the slightly-more-massive scalar cousins to the isoscalar pseudoscalars. Just a thought.

The graph in the Appendix of your work shows large descrepancies around the A = 40, Z = 20 and A = 32, Z = 16 positions that are opposite in magnitude. Why such a powerful gradient in the descrepancy there? Is there some waveform in the data with a central node at A = 36, Z = 18, and end nodes at A = 24, Z = 12 and A = 48, Z = 24? All of those are at positions where the nucleus, as a system, would be isoscalar.

[arivero]

Originally posted by mormonator_rm
(547.30 MeV). This basically says that f0(980) and f0(600) i.e. sigma are the slightly-more-massive scalar cousins to the isoscalar pseudoscalars. Just a thought.

Hmm it seems a good clue.


The graph in the Appendix of your work shows large descrepancies around the A = 40, Z = 20 and A = 32, Z = 16 positions that are opposite in magnitude. Why such a powerful gradient in the descrepancy there? Is there some waveform in the data with a central node at A = 36, Z = 18, and end nodes at A = 24, Z = 12 and A = 48, Z = 24? All of those are at positions where the nucleus, as a system, would be isoscalar

All the data below A=40 is definitely in the ascending part of the energy per nucleon so, to me, it is not surprising to find different tendences. As far a I understand, the droplet models, such as the one in the appendix, are mostly macroscopic liquid drop models (thus "long waveforms") with a microscopic tuning (ie aditional parameters) to get the shell structure. But I am not sure if they fix some parameter in the A=24..48 range; in principle the lower magic numbers (Zor N=2,8,20) can be got from the harmonic oscilator potential directly.

A question... I am afraid I will do some blatant mistake if I do not fix rightly my jargon. I mean, all the "isoescalar", "pseudoescalar", etc. surely do not follow exactly the QFT conventions. Can you sugest some lectures (in the net or in the Physical Review, if possible) I should do in order to get the slang?

[mormonator_rm]

The Physical Review is full of this kind of jargon. Basically, these are just ways of defining particular groups of hadrons. When I say "isoscalar", for example, I am referring to those hadrons that have an isospin number equal to zero. When I say "pseudoscalar", I am referring to the group of hadrons that share the quantum numbers j = 0, negative parity and positive conjugation (hence, a "false" scalar because it has no spin and unnatural parity at the same time). I don't know if there is a particular place that you can find a list of their meanings; I just learned them by experience over time. All you really need to know is that scalars have total spin of zero, vectors have total spin of one, and tensors have total spin of two. Intrinsically, they also have natural parity (0+, 1-, 2+, ...). The pseudo-anything particles have unnatural parity for that total spin state (i.e. pseudoscalars are 0-, pseudovectors are 1+, etc...). As far as isospin goes, in every multiplet of mesons you have members with isospin equal to zero (called isosinglets or isoscalars), and you have members with isospin equal to one (called isotriplets or isovectors). You also have members with isospin equal to 1/2 (called isodoublets or isospinors?). These naming schemes of groups are consistent for all mesons. Now, baryons are kind of tricky, although the isospin rules still work (except for with the isospin = 3/2 members, which I do not know what they are called), because they are fermions. I do not work much with baryons other than the proton, so I do not know any general names (other than the multiplet quantum number states themselves).

[arivero]

I think I get it. It is as QFT on one side, but on another you must always count the isospin. I have got at home the Particle Listings (nice fellows, the CERN librarians), so I am already being flooded with the jargon.

The sequence scalar, vector, tensor, pseudovector, pseudoescalar is used MathPhys. too

[mormonator_rm]

Originally posted by arivero
All the data below A=40 is definitely in the ascending part of the energy per nucleon so, to me, it is not surprising to find different tendences. As far a I understand, the droplet models, such as the one in the appendix, are mostly macroscopic liquid drop models (thus "long waveforms") with a microscopic tuning (ie aditional parameters) to get the shell structure. But I am not sure if they fix some parameter in the A=24..48 range; in principle the lower magic numbers (Zor N=2,8,20) can be got from the harmonic oscilator potential directly.

Well, those first few make great sense. I would expect those to correspond to full nucleon shells. And the harmonic oscillator is probably the best approximation of the strong force that we know of, so that follows naturally.

I was thinking the other day about the sigma meson again. This is kind of going against the idea of an independent sigma (i.e. f0(600)), but it should be considered. f0(600) is an incredibly wide particle (short-lived), possibly because it only exists momentarily at the vertex of two-pion exchange. Another thought is that perhaps it occurs as a virtual particle (where only enough energy exists to create the two pions; the bound state in S-wave could give you a sigma meson below the sigma mass). In either of these cases, the sigma is reduced to a fancy trick, just like it is often considered. I don't like that idea by itself, rather it would be cool if sigma could be used that way but also be shown as a real particle. It would decay only to neutral pions via S-wave, and to photons. If it is a bound molecule of two pions, then decay to photons should be suppressed by its wavefunction.

[arivero]

Indeed the sigma=two pions seems an interesting option to keep in mind.

BTW, could you mind email me privately just to know who I have been speaking to? It is no a problem, to me, to quote "mormonator_rm" as a reference, but perhaps some referee could feel it, ehem, unappropiate.

[Kaspah_2k]

its quite ironic if your sitting on your computer and saying that CERN isnt useful. well they invented the ARPANET (some of you must remember that) which was just two old chunky computers stuck in two universities on two sides of america. they then tried to pass a data stream between the two and whatdoyaknow....the internet was born.

Particle physics is used for alot more things than you or me know.

But CERN have went a little bit behind in the race to find particles smaller that neutrinos and all those other new particles like 'Gamma' 'Zeron' and the most famous 'Omega'.

Fermilab are building their brand new Particle accelorator and its meant to be way better than CERN's.

i mean, this must be a good thing because each company is trying to outdo the other and in admist of all their corporate wranglings, its we the consumerate populous that benefits these projects.

remember that the next time you send an email...[8)]

[neutroncount]

Actually it's CERN that is building the LHC (large Hadron Collider) that is suppose to be seven (or is it ten) times as powerful as Fermilabs best attemps. As a Fermilab physicist was quoted saying "In the end, CERN is going to blow us out of the water".

[suyver]

Originally posted by Kaspah_2k
But CERN have went a little bit behind in the race to find particles smaller that neutrinos and all those other new particles like 'Gamma' 'Zeron' and the most famous 'Omega'.

Last I heard, a neutrino still wasn't composite and still had zero size. What particle is smaller than a neutrino???

Also, a gamma is a photon; a quite well-known partice even before CERN was build...

I have left the subatomic field, so I may have missed it, but what's a 'zeron'?