As far as I’ve been able to tell, there’s still nothing definitive one way or the other about the SM Higgs, as the experiments continue to analyze data from the now-finished 2011 pp run. Starting Monday is the HCP 2011 conference which at one point seemed to be a possible venue for announcement of confirmation of hints from early this summer of a Higgs around 140 GeV or so. Those hints disappeared later in the summer, so conventional wisdom recently has been that not much new will come out next week in Paris. A new blog entry from one of the organizers refers to this disappointment, leading to worries about conference attendance, but adds some dramatic and mysterious news at the end. It seems that some experimental collaboration requested a last-minute slot at the conference to unveil a new result that might be the highlight of the conference. They’re on for 15 minutes on Monday, still not announced which collaboration this is, who the speaker is, or what their title is. This may very well have nothing to do with the Higgs: maybe something else travels faster than the speed of light…
At HCP2011, ATLAS will have new results from the H->ZZ->llnunu channel (already released, see here) and from the H->ZZ->llqq channel. Unfortunately neither of these are relevant to the low mass region where the Higgs is believed to be hiding. I don’t know what CMS has up its sleeve. One other thing that will be released is the combination of ATLAS and CMS summer conference data, which will exclude the Higgs at 95% confidence level from 141-476 GeV (and come very close to this exclusion down to about 135 GeV).
It looks like release of new data in the channels that are sensitive to a low mass Higgs will wait longer, until the experiments have had a chance to do some analysis on the entire 2011 data set. Mid-December has been rumored as a date, and a logical bet would be that the CERN Council week would be the time for this, in particular at the Scientific Policy Committee meeting on December 12-13. Rumors going around about this are that there’s still nothing definitive in the crucial H->gammagamma channel, and that in the H->ZZ->llll “golden channel” (very low background), one experiment is seeing no excess at low mass, the other is seeing an excess. Higher quality, better informed rumors are encouraged…
Nature reports here on the discussion at CERN about what to do in the (wonderfully exciting…) event that the SM Higgs is not seen. The first action they’re taking is semantic: if no Higgs is seen at the 95% confidence level, instead of saying that this “excludes” the Higgs, they will announce that it “disfavours” it. So, the first reaction will not be jumping for joy, but a defensive one about how it might still be there.
Whatever comes out in December, I hear the plan is to wait for the Moriond conference at the beginning of March to release a result combining data from all channels (separately for each experiment). The Tevatron may have a result to release then too. Philip Gibbs will then swing into action for the full combination.
Update: Via Philip Gibbs, this talk includes the information that “The CERN DG has requested updates for December council”. Not clear to me if the plan is to release these publicly, or to try and keep them confidential (which may not be easy…).
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