well, thank you very much for the encouragement. I thought the matter could be of interest to a wider audience than other typical posts, so I made a little extra effort at making this both readable and informative…

About the nitty gritty: when I said the consensus is nowadays to prefer direct cross section measurements to tau decay information, I am reporting Massimo’s statement. He does know the details of the theoretical debate on this issue of course, but he might have been putting some personal flavor in his talk…

As for string theory coming to the rescue in low-energy QCD, I am all in favor of it if it happens: that’s really a “hic sunt leones” for HEP nowadays. At a panel discussion in PPC2008 the question was asked on what way to best invest one billion dollar to further our advancement in the understanding of HEP and cosmology. After hearing about giant space telescopes, cosmic ray exeperiments and TeV energy leptonic colliders, I was the only one who mentioned saving a fifth of the sum to build new experiments to understand low-energy hadronic interactions better!

Cheers,
T.

I understand that it isn’t the intention of this blog to get into deep discussions over the nitty-gritty, but when you say that the general consensus is to discard the tau data, this is not reflected in the current (July 2007) Particle Data Group assessment:
“The discrepancy between the e+e− and τ -based determinations of aHad µ [LO] is currently unexplained. It may be indicative of problems with one or both data sets. It may also suggest the need for additional isospin-violating corrections to the τ data. Forthcoming low-energy e+e− and τ data may help to resolve this discrepancy and should reduce the hadronic uncertainty.” See Page 4 of
http://pdg.lbl.gov/2007/reviews/g-2_s004219.pdf

In Part 1 you said about the SM “This isn’t string theory”, but the ironic thing (and I’m no promoter of string theory) is that probably the one area where string theory seems to show some practical promise is precisely in getting a better handle on low-energy QCD behaviour. If this is really true, it would be an interesting demonstration if it could be successfully applied to this sort of problem. Perhaps a competent string theorist could comment on this.

Nitty gritty over!. I think this article could be your best yet!. You are doing a tremenduous job!

Whether there is or not a Higgs, I think is another matter. But I do believe we will find one… It might not be what we thought it is, though.

Cheers,
T.

In other words, you now suspect that the fairy particle will be found under 130GeV at the LHC! Hah, hah!