Comparing Combos

The Tevatron Higgs Combination is up, so time to compare with my prediction

Here is mine from last week

And now the official deal

As you can see I got it pretty close. The main difference is that the peak excesses at 130 GeV and 140 GeV are a shade more pronounced on the official plot. The difference is about half a sigma. That is good news because it enhances the chance of new physics (such as a Higgs) in those regions.

11 Responses to Comparing Combos

  1. Ervin Goldfain says:


    How can two peaks barely above background enhance the chance for new physics? What am I missing here?



  2. Luboš Motl says:

    Congratulations, closer than I expected. 😉 Still listening to the plenary talks…

  3. Luboš Motl says:

    By the way, you did the right thing not to make a bet about the exclusion of 140 or 145 GeV which of course wasn’t excluded. 😉

    The first question is about the 114-137 press release of the Tevatron – and the main final speaker on behalf of the Tevatron doesn’t even know the press release. 😉 Obviously living in a different world. He says the press release is based on g-fitter fit.

    • Philip Gibbs says:

      I had the right idea except that they were basing it on an even lower (one-sigma) exceptance region than I expected. The press release did say “most likely” which is a correct way to describe the one-sigma region, but it is much weaker than the 95% exclusion than most people read into it, and weaker even than the 90% exclusion that I suggested.

      I was right that it was a combination of direct searches and precision measurements.

    • Luboš Motl says:

      Dear Phil, you were not saying that it would be a combination. You were saying that the 114-137 interval came as an exclusion from direct searches. (And that they would also show another thing based on precision physics.)

  4. Luboš Motl says:

    Murray of the LHC didn’t present his combo – not ready. But he said: Be aware, there’s lots of nonsense on the Internet.

    For example, there is a web page with a combination based on absolutely nothing, he warned. But don’t be scared, Phil, it’s none of our blogs. The website with nonsensical LHC combinations based on nothing is the CERN central web page. 🙂 Oops.

    Funnily, he chose the same value 144 GeV as I did for the largest total excess in both detectors. That shows that your digitization was probably right. 🙂

    • Philip Gibbs says:

      He is probably referring to the fact that my chart was shown on a slide at one of the LHC operation team meetings, presumably with appropriate comments.

      Everything I have done has been accompanied with suitable caveats. The correlation of background uncertainties and the use of Look Elsewhere Effect could account for the differences seen here. It looks like the simple combination usually makes the result give a bit more exclusion than it should, so this should be born in mind, especially for the “standard model killer” plot. We should also remember that the combination method is equivalent to what the global fit groups use (with disclaimers about correlations) so it is not quite nonsense.

      Of course I agree that the official combination will be better and is worth looking forward too, but more data will make a much bigger difference.

  5. […] muy desencaminada, basta comparar a vista las dos figuras quye él mismo muestra en ”Comparing Combos,” viXra log, July 27, 2011. Enhorabuena, Philip. ¿Buen hacer o coincidencia? La estadística […]

  6. […] formulas I used in those combinations were just quick guesses but they worked quite well for the Tevatron combination of CDF and Dzero Higgs results. In two or three weeks the LHC will […]

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