Tevatron Higgs Results

The combined D0 + CDF Tevatron results on the Higgs are scheduled to be announced Wednesday, but it looks like this web-page may have jumped the gun a bit, listing the new results (based on “up to 10 inverse fb”) as:

SM Higgs is excluded between 147 and 179 GeV there is a greater than 2-sigma excess observed at low mass.

The summer 2011 combination excluded at 95% the mass range 156-177 GeV, so the new results extend this slightly higher and 11 9 GeV lower. The most intriguing aspect is the “2-sigma excess at low mass”, which is about what you might expect them to be seeing if there really is a 125-6 GeV Higgs as the LHC data suggests. In the H->b bbar channel that the Tevatron is most sensitive to (and that the LHC is not sensitive to) the expected signal is very wide, not allowing much of a fix on the Higgs mass (see Resonaances for more of an explanation of this).

Details to appear Wednesday, at

http://tevnphwg.fnal.gov/results/SM_Higgs_Winter_12/

Update: Matt Strassler has written a long posting to provide context and caveats for these results here.

Update: Results described here a couple days ago now official (2.2 sigma). Details at the usual recommended places (Dorigo, Gibbs, Jester, Strassler). I’m teaching a class, then off on a plane…

This entry was posted in Experimental HEP News. Bookmark the permalink.

15 Responses to Tevatron Higgs Results

  1. Nex says:

    If more LHC data eventually rules out Higgs around 125 GeV the fact that pretty much every experiment is seeing some bump there will need good explanation.

  2. E.S. says:

    156-147 = 9 …

  3. Peter Woit says:

    E.S.,

    Oops, I supposed I should proof-read these things… Fixed.

  4. Craig says:

    Nex,
    Re a good explanation. There were a bundle of experiments that reported observation of a pentaquark a few years back. Eventually some negative searches were reported, from Fermilab experiments and elsewhere, and the pentaquark disappeared. I don’t recall any of the experiments that reported positive sightings providing good explanations, or any explanations, of why they saw something. Of course, although the pentaquark “discovery” did make the news, it’s not quite the Higgs!

  5. JRPS says:

    To Craig:

    You are right not all experiments for the pentaquark gave detailed explanations of why they saw something. But some people closely related to the experimentalists did, despite initially supporting the pentaquark . Some of these papers appeared in nucl-th and may have been unnoticed to people reading hep-th or even hep-ph. For instance I would suggest Phys.Rev.Lett. 105 (2010) 092001, e-Print: arXiv:1008.4978 [nucl-th] (To my view that was the last nail in the coffin, but came out too late, when basically just one experiment still supported the pentaquark). Of course, showing why a result which nobody believes anymore is wrong, does not get much attention. But that kind of works are done. I agree with you it would be nicer if the experimentalists had done it themselves. Some of them do and some don’t.

    This is an example of why I give little significance to the “confidence level” claims. But there are many others. Quite often in Particle Physics we have seen “many sigma” and “99% C.L.” claims that go away due to some systematic effect, which is well explained later… or not (the pentaquark, R_b, FTL neutrinos, and so on…). You can make a fantastic job with statistics, that is useless if you do not understand your systematics.

  6. guest says:

    Hype about strings=BAD. Hype about the Tevatron=GOOD.

  7. guest says:

    Or in other words: when will you tell your blog readers that the latest splash on Higgs searches at Moriond came from ATLAS results?

  8. jpd says:

    results from strings=NONE. results from the Tevatron=INTERESTING.

  9. Peter Woit says:

    guest,

    1. I’m on vacation.
    2. As usual I suggested other places that do cover these things much better than I do, including the ATLAS results in detail.
    3. I try to post news here that is not available elsewhere. The Tevatron news was a good example
    4. It’s great that ATLAS is able to rule out lower mass ranges, but that now is not where people are expecting to see something. The big question is what is going on at 125 GeV, is it the Higgs? And ATLAS has nothing much new to say there.
    5. The Tevatron seeing a marginal signal in a new channel, consistent with 125 GeV Higgs, is news.
    6. This is probably the last major Tevatron result we’ll ever hear. The victors at CERN who have put it out of business should be gracious.
    7. I don’t think there’s any danger that ATLAS and CMS results at the LHC will receive insufficient attention.

    Back to vacation…

  10. guest says:

    Thanks for the detailed answer!

    1. Apologies.
    2. Yep.
    3. OK
    4. Strongly disagree. Among other reasons ruling out that extra chunk increases the significance of the bumps, by reducing the LEE. And ATLAS had also the potential
    of directly reducing the significance by enlarging the dataset analyzed.
    5. Yes, it’s news. Marginal news.
    6. On this I agree.
    7. Right.

    Thanks in any case for the info.

  11. anonymous says:

    Who cares about puny 2-sigma Higgs results? Have you seen Daya Bay’s very convincing 5-sigma neutrino result? That just killed the tribimaximal mixing theory dead and gone and opens the door to studying CP violation in the leptons!

  12. guest says:

    Who cares? Anyone with the right understanding on what’s more fundamentally important.

  13. A. says:

    Totally off-topic, sorry, but I just saw this postdoc ad. for a position in “the philosophy of cosmology” in DAMTP. Is this just a very silly choice of title or has Cambridge really gone down hill?

    http://www.damtp.cam.ac.uk/vacancy/#RAPhilosophyCosmology

  14. Chris Oakley says:

    A,

    I would opt for the latter explanation.

  15. Andym says:

    Definitely, downhill all the way.