This Week’s Rumor

The start of the LHC 2012 physics run is still a while off, scheduled for around the beginning of April, with beam energy likely raised a bit, to 8 TeV total in the center of mass. So, it’s going to be quite a few more months before the LHC experiments have enough new data to analyze that will allow a conclusive determination of whether the evidence seen for a Higgs around 125 GeV is confirmed, with a significance high enough to claim discovery.

The results announced on December 13 were preliminary, and more complete analyses are underway, with results to be announced relatively soon. This week’s rumor is that the full CMS Higgs to gamma-gamma analysis is showing a stronger signal than the preliminary version. The bump has moved up a bit, from 123.5 GeV to 124 GeV, and the local significance is up from 2.3 to 3 sigma, with look elsewhere effect up from .8 sigma to 2.0 sigma. This strengthens a bit the evidence for a Higgs around 125 GeV. However, the best fit size of the bump is, as with ATLAS, about twice what the SM predicts. The errors are large, so quite possibly both experiments just got a bit lucky, in which case the first few months of 2012 data may not quickly add much to the significance of the signal.

For detailed discussion of issues surrounding the Higgs analyses, see this week’s workshop in Zurich: Higgs search confronts theory.

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16 Responses to This Week’s Rumor

  1. Pingback: Peter Watkins and Z bosons at Trinity College Dublin « Antimatter

  2. Mottled Lobush says:

    You meant 8 Tev c.m. energy.

  3. A Physicist says:

    It sounds bit like that in the rush to include all the Higgs channels, CMS did not do a good enough job of the important ones …

  4. Paolo Valtancoli says:

    Is it possible experimentally to distinguish between a fundamental or a composite Higgs Boson ?

  5. Peter Woit says:

    Paolo,

    Theories where the Higgs is not the quantum of an elementary field will often have limits in which it behaves like one, so, generically you should be able to tell the difference in principle, but in practice you may just be able to put bounds on some compositeness scale. If there really is something at 125 GeV, the focus for many years will be on measuring its properties to see if they’re precisely those of an SM Higgs (or a SUSY variant). Hopefully some difference will be found, otherwise life will get very boring.

  6. Trulo says:

    Although the Higgs boson is obviously the star now, and for some time to come, I guess the collaborations are still working hard on putting bounds on SUSY parameters. Are there any news on that front?

  7. Peter Woit says:

    Trulo,

    I haven’t heard anything, but the time to expect announcements is probably Moriond in early March.

    My understanding is that the negative results of the initial SUSY searches won’t be strengthened very much by doing the same analyses with more data (since the cross-sections they were looking for were strongly-interacting, so large). So, now the question is about different analyses that look for SUSY in different ways, but I don’t know much about this. We’ll probably hear from Matt Strassler more about this as results get released.

  8. harryb says:

    Although most associated with the US Presidential Election betting, as we start the year I thought I would have a look at what Intrade markets put the odds at on the Higgs boson turning up in 2012 (“discovery published in major scientific journal” original criterion, now 5 sigma, peer-reviewed etc being added to the rules).

    Currently the market gives it a 40% chance this year, down from highs of about 70% in December (volatility presumably due to all the mid Dec announcements).

    Interestingly, there is also a market on SUSY particles being discovered. It has been inactive for a year, and the starting price offered is 25% chance.

    So if our String Theory colleagues want to fill their boots I assume they will now rush off to Intrade and buy heavily into those shares….except the market so far has seen no activity at all. Hmm, seems the iron faith in ST is not translating into even one adherent parting with a single buck.

    Even unbelievers ought to dive in at this level- if nothing else as an emotional hedge against ST actually pulling off a SUSY triumph. At least we would have money in our pockets as a consolation.

    Of course, alternatively Mr Woit and colleagues ought to sell heavily at 25% – still good money if we are true to our convictions…

    Be worth watching these markets from time to time in 2012 in line with hype / discoveries.

  9. Proudmemberofthecult says:

    @ harryb

    or the string theorists are too busy doing science to look for internet sites where one can bet…

  10. harryb says:

    @Proudmemberofthecult

    The comment re betting was not meant to be flippant – but I take your point.

    It was interesting to note that there is a live market on Higgs outcome which is remarkable given its potential obscurity. So Higgs acceptance or expectation appears to have entered to a certain extent the mainstream – so much so people will actually bet their own money on it being found.

    SUSY particles remain esoterica, but there is a market for them which you can argue is credibility of a sort.

    Genuinely intrigued that erstwhile obscure particle physics has already attained a status where likelihood of occurence or major announcement is being subjected to mainstream economic probablistics using buyer-seller dynamics (“betting”). However, markets remain thin which makes them of limited value – for now.

    Any odds offered on a solution to the Fermi paradox after the exo-planet discoveries of this week?

  11. Jason says:

    As an economist and peruser of physics blogs I thought Higgs at 40% for 2012 was a great bet a few weeks ago when I first saw it, but decided against wagering when I realized the total number of contracts available at that price was so small that it wasn’t worth my time to click (even were you certain of a published 5-sigma result in 2012 and bought all possible shares you would stand to gain about $250, and the average share price would be around 70%).

     

    The lesson here is that you should look at the number of contracts offered before inferring that the listed Intrade price represents the market’s assessment of the probability that the event will occur.

  12. Jeff M says:

    As for the Fermi paradox, not really sure why exactly this is a paradox. Assuming 1,000,000 advanced civilizations in the Milky Way right now, and assuming that only 1/2 the Milky Way is habitable (over compensating for the black hole at the center), a seat of the pants estimate gets me that the civilizations are separated by more than 300 light years on average. Can’t see that the odds are very high we would notice anything. Boy that light speed limit is annoying 🙂

    Me, I figure there really are a whole lot of planets with life out there, and a whole lot with “intelligent” life too, since we now know that planets are ubiquitous.

  13. Peter Woit says:

    I better stop this Fermi paradox thing right here. It’s really, really far off-topic…

  14. Jeff M says:

    Sorry Peter, couldn’t resist, promise to stay on topic in the future.

  15. Pingback: Rumores y nueva información no oficial sobre la búsqueda del bosón de Higgs « Francis (th)E mule Science's News

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