of course publishing agreement with the SM is easier than forcing an anomaly through a collaboration. Most researches in science are plagued by the decision process of the people doing the analysis, in a number of ways: choice of what to work on, for instance, is a usually overlooked source of bias. I think Physics is not immune, and we can only rely to the fair dealing of the scientists involved.

Cheers,
T.

I’ve been sort of slow in replying to this thread – and I think it was a lucky idea, because an interesting discussion has grown by itself and answers (with even links to papers, thanks Anomalous!) have been provided. I could do no better, so thanks to all involved.

Cheers,
T.

Thanks a lot for your helpful post. Of course, you are right. So, let us wait and see.

Jon

“the Lagrangian can become non-perturbative at far lower values of the Higgs mass. You can see this from \sqrt{\lambda}=M/\sqrt{2}v with v=246 GeV.”

You have to be careful; the coupling constant $\lambda$ is not the real effective expansion parameter in your Feynman diagram expansion. The parameter that effectively governs succeeding terms in the expansion of a $\lambda \phi^4$ theory is $\lambda / 16 \pi^{2}$. See section 4.4 thru 4.7 of the book by Ramond: “Field Theory: A Modern Primer” for a detailed study of the perturbative expansion of $\lambda \phi^4$ and its renormalization.

This is actually a common property of field theories, that the effective expansion parameter is not just the Lagrangian coupling but includes inverse powers of factors of $4\pi$. Take Quantum Electrodynamics: the Lagrangian coupling at the vertices is “e”, but the expansion parameter in the Feynman diagram expansion for QED is “$\alpha = e^{2}/(4\pi)$”. Incidentally, the Lagrangian coupling parameter for QED is not that small. For $\alpha$ = 1/137 you can see that “e” is about 1/3, or in other words about the same value as the parameter in the 1/N expansion of QCD [this observation is known as "Coleman's joke" among field theorists].

You should not worry. The unitarity bounds that Guess Who quotes above are based on calculations that got all their factors of $4\pi$ right, and give about the number he quotes. For example see:
-Weak Interactions at Very High-Energies: The Role of the Higgs -Boson Mass.
-Benjamin W. Lee, C. Quigg, H.B. Thacker (Fermilab) . -FERMILAB-PUB-77-030-THY, FERMILAB-PUB-77-030-T, Mar -1977. 50pp.
-Published in Phys.Rev.D16:1519,1977.
-TOPCITE = 1000+

And yes, a lot of LHC studies have been done to convince the experimentalists that they can see a Higgs up to that mass!

Jon

I agree with your hunch that D0 found that their background model
required more work is the most probable explanation for the delay.

Any comment about what conclusions should be drawn when a published result cannot be updated without having to change background rate/shape predictions beyond the systematic range listed in the PRL? One might conjecture that in the current climate at the tevatron the quickest path to publication (a.k.a. job advancement) is to have excellent agreement with SM predictions.

hep skeptic

Jon

unfortunately, no. I was betting on a result for LP07 from them too, but if two (early unconfirmed rumors of excesses) and two (no news) is four, I bet they found that their own background model required more work. Another interpretation could be that they are trying to include all the data they can in a more solid new result. In both cases, I am quite interested in seeing what they will publish.

Cheers,
T.