Mass generation and supersymmetry

30/07/2010

I have uploaded a paper on arxiv with a new theorem of mine. I have already exposed the idea in this blog but, so far, I have had no much time to make it mathematically sound.  The point is that the mechanism I have found that gives mass to Yang-Mills and scalar fields implies supersymmetry. That is, if I try to apply it to the simplest gauge theory, in a limit of a strong self-interaction of a massless Higgs field, all the fields entering into the theory acquire identical masses  and the couplings settle down to the proper values for a supersymmetric model. Being this result so striking, I was forced to produce a theorem at the classical level, as generally done with the standard Higgs mechanism, and let it widely known. My next step is to improve the presentation and extend this result after a fully quantum treatment. This is possible as I have already shown in the case of a Yang-Mills theory.

My view is that just a mechanism could be seen in Nature to produce masses and I expect that this is the same already seen for QCD. So, supersymmetry is mandatory. This will imply a further effort for people at work to uncover Higgs particle as they should also say to us what kind of self-interaction is in action here and if it is a supersymmetric particle, as it should.

The interesting point is that all the burden of the spectrum of the standard model will rely, not on the mechanism that generates masses but on the part of the model that breaks supersymmetry.

Interesting developments are expected in the future. Higgs is always Higgs but a rather symmetric one. So, stay tuned!


Rumors on Higgs at Tevatron

10/07/2010

It is not my habit to put rumors about as my readers know, but the news is really sensational. Tommaso Dorigo in his blog told  that rumors are leaking about a light Higgs seen in one of the two collaborations at Tevatron. Tommaso is working there too.

Rumors say of a Higgs particle having a mass of 115 GeV, very near the limit identified at LEP and so a reason to regret for CERN. This will support the view of a supersymmetric particle. Supersymmetry, for consistency reasons, requires Higgs to be light. On the other side, we know that the Standard Model cannot hold with a superheavy Higgs particle. This implies that a similar identification at LHC should be near and this machine should work out supersymmetry in all its glory.

Finally, let me point out a similar post by the Czech guy.

Update: Fermilab denied rumors about Higgs finding at Tevatron (see here).


QCD 10

09/07/2010

Last week I have been in Montpellier (France). The occasion  was one of the most important as it was 25th anniversary of QCD Conference series that are held there with two year cadence. The organizer is Stephan Narison and this was QCD 10. Thanks to Stephan, it is the third time that I have the opportunity to go to Montpellier to talk with him and other fine people about QCD. I have this opportunity also to learn a lot about this matter and to improve the quality of my research. This time, Stephan managed also to remember that are passed 31 years since the seminal SVZ paper on sum rules in QCD by Misha Shifman, Arkady Vainshtein and Valentine Zakharov that made a major breakthrough in the field. I have the luck to exchange some words with Prof. Zakharov and he was really illuminating about the current situation of different aspects of this field. I hope to see him in Ghent (Belgium) in the fall this year. He is one of the organizer of the conference The Many Faces of QCD and I am a registered participant. Misha Shifman was also there and showed how a track toward understanding confinement can be pursued passing through supersymmetry (see here). I take this chance to remember that Shifman, Vainshtein and Zakharov achieved a fundamental result in computing the exact beta function of supersymmetric QCD (see here) but to these notable names we must add the name of Novikov.

The conference has been very well organized and the atmosphere was really friendly. Scientific content was absolutely interesting and some experimental groups presented firstly some new results here. You can take a look at all the talks here. Mine is this. About the questions that mostly urge me, I was impressed again by a talk of  COMPASS Collaboration (see also here). They confirm their finding that gluons do not seem to weigh too much in determining proton spin. As you know, this is what I expect from my theoretical analysis for low-energy QCD. Proton spin is mostly due to quark spins and orbital motion, the latter for the larger part.

Results from KLOE-2, at INFN of Frascati (Italy), are really striking. Talk is here. They have increasing evidence that \sigma resonance is indeed a glueball but they are not claiming this yet. The track they followed till now is a really smart one and implies studies of \eta' decay and studies of the invariant mass of the \pi\pi pair obtained from it. They also showed that \eta' has a significant glue component and this would imply (see also my talk), that its main decay process produces a \sigma particle. Indeed, what these researchers have found is the first clear evidence of the analogous of an excited atom in strong interactions and the corresponding decay into the emission of the corresponding force carrier. Their approach is really striking and it is my personal conviction that a lot more should be expected from this collaboration ending a long research for the first glueball. But strongly linked to this, there is an interesting theoretical analysis by Vincent Mathieu together with Vicente Vento that strongly support all these ideas about \eta' nature. Vincent gave the talk and we have had a very interesting exchange about. He was so kind to inform me about the conference at Ghent. We have had an interesting evening at a restaurant in Montpellier together with other very nice fellows (see below) about a riddle on a row of physicists, the colors of their hats and how to save their lives from a mad man aiming to kill all of them.

When you go to a conference like this, the chance to meet very interesting people is the highest. Indeed, I have had the opportunity to meet three Italian researchers: Francesco Dettori at LHCb from University of Cagliari (Italy), Luca Mucibello at CMS from University of Antwerpen (Belgium) and Silvia Pisano from Orsay (France).  We have had a lot of good time and discussions of any kind, ranging from physics to politics and other. I am aware that science is an international enterprise but I am Italian and is really a satisfaction to see such smart young countrymen being part of it notwithstanding mortifications our politicians are giving them and to research at large. On a similar side, I have also met people like Mihail Iliescu that is working at INFN and after a lot of time has not yet a position. He told me that he lost a permanent position in Romania after heavy cuts from their government. He is collaborating to a very interesting experiment about Kaon atoms with SIDDHARTA Collaboration.

The Conference was concluded with a dinner in a beautiful place near Montpellier. Stephan presented some dances from Madagascar while wine and food were really satisfactory. Then, after a walk downtown and a beer offered by Francesco, we left with the aim to maintain our bounds somehow.

Again a great experience in Montpellier. Thank you very much, Stephan!


A crack in quantum electrodynamics

08/07/2010

It is well-known that quantum electrodynamics is the flagship of all quantum field theories. The article in Wikipedia has been flagged good article after an important review process and so it is worthwhile to read. I received as usual the table of contents of Nature for this week and I have found a striking paper. You will need a subscription to read it in full but the first part is readable for free and the conclusions by these authors are striking. The idea is smart as they consider an atom formed by a proton and a muon rather than the usual hydrogen atom. If you remember standard Bohr formula for the radius, this goes as 1/m and so this is smaller for the muon atom making possible a more direct probing of the finite size of the proton. These authors do fine spectroscopy on it measuring the Lamb shift. What they find is in disagreement with QED computations and so it is possible to conclude that this discrepancy may arise either directly from the theory or, for some reason, one has to shift Rydberg constant. This is a relevant crack into a cherished theory and so, it will appear interesting to work out a possible understanding. It should be said, even if on a more complex side, that muon g-factor could be a possible clue for new physics departing from the Standard Model. Indeed, it seems that, in some way to be clarified, muons are the key.

Update: There is a nice article at Physics World. A worthwhile reading.


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