New Higgs Mass Limits

The new combined CDF/D0 Higgs mass limits are out, there’s a paper here. At a confidence level of 95%, a standard model Higgs is excluded for a mass range between 160 and 170 GeV. At a confidence level of 90%, the range excluded is 157-181 GeV. Precision electroweak measurements already constrain the Higgs mass to lie below 185 GeV (at 95% confidence level).

Taken all together, it now looks likely that, if there is a standard model Higgs, its mass is in the region 114-157 GeV. With the data they have analyzed so far, the Tevatron experiments are only able to say that the cross-section for producing a SM Higgs over this mass region cannot be more than 2-3 times the SM value. They still have more data in hand to analyze, and the machine continues to run well. It will likely stay in operation at least a couple more years, possibly doubling the number of collisions already collected. The paper promises:

The sensitivity of our combined search is expected to grow substantially in the near future with the additional luminosity already recorded at the Tevatron and not yet analyzed, and with additional improvements of our analysis techniques which will be propagated in the current and future analyses.

Now, we just need to hope that they don’t find the SM Higgs in this remaining region, which would make things really interesting…

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9 Responses to New Higgs Mass Limits

  1. Shantanu says:

    Peter, doesn’t this rule out (or severely constrain) MSSM? If I remember right, MSSM has a some upper bound on Higgs boson mass in the region already excluded, but maybe others should clarify.

  2. Peter Woit says:

    Shantanu,

    I don’t think this says much of anything about the MSSM. There the SM-like Higgs is supposed to be light, you have to tune things to get it above the LEP limit.

  3. Anon says:

    Unrelated, but the talks at the IHES conference on Grothendieck are available online at:

    http://video.google.com/videosearch?q=grothendieck&hl=en&emb=0&aq=-1&oq=#q=grothendieck&hl=en&emb=0&aq=-1&oq=&start=10

  4. Peter Woit says:

    Thanks!

    A somewhat better link for these might be

    http://www.dailymotion.com/visited/Ihes_science/1

  5. Nameless says:

    According to the Fermilab press release, they expect to triple the integrated luminosity by the end of 2010, bringing it up to 10 fb^-1 per experiment.

    If it’s not there, CDF/D0 should be able to rule it out at 95% CL before LHC has a chance to say anything definitive. If it’s there and it’s sufficiently heavy (say, 150 GeV), they might be able to claim evidence of Higgs at 3 sigma. However, 10 fb^-1 would be insufficient to claim discovery at 5 sigma, whatever the mass.

  6. chris says:

    “Precision electroweak measurements already constrain the Higgs mass to lie below 185 GeV”

    you forgot a very essential ‘standard model’ here. in SM extensions, there is no problem obtaining Higgs mass as large as 600GeV

  7. Arun says:

    Happy 5th birthday!

  8. diver says:

    I remember Alain Connes has a paper in which he also predicts the mass of Higgs. Does anyone know what was his prediction? and whether it is still within the viable range?

  9. Peter Woit says:

    diver,

    Connes’s prediction was for about 170 GeV, which is in the ruled out range. This was even true last summer, and Connes acknowledges this, see

    http://noncommutativegeometry.blogspot.com/2008/08/irony.html