As part of the CERN Council activities this week, there will be a session held with a live webcast tomorrow on Status of the LHC and Experiments. I’m hearing that there will be news about the Higgs from ATLAS: new results for the high statistics gamma-gamma and ZZ channels. These were expected for HCP2012 last month but not ready then.
If you can’t watch the CERN talks, the KITP tomorrow at 11:15 am has scheduled a talk on “New (!!) ATLAS Diphoton and ZZ Results”.
Update: This promises to be quite interesting. ATLAS is seeing a 3 sigma difference between the Higgs mass seen in the gamma-gamma channel and in the ZZ channel. They’ve been trying hard to check all possible systematic effects that could explain this, but it won’t go away, so they’ve decided to go ahead and report the results tomorrow. Probably nothing, but if CMS is seeing anything similar and it is still there in their analysis of the rest of this year’s data, that would be huge. I don’t know of any sensible model that would lead to a real effect like this, but who knows…
Update: The new ATLAS results don’t seem to be available online anywhere, but Jester and Matt Strassler report the details from today’s webcast. ATLAS has the Higgs at 126.6 GeV in gamma-gamma, at 123.5 in ZZ, difference is 2.7 sigma. The ZZ signal strength is right in line with SM predictions, the gamma-gamma signal strength is about 2 sigma high. Odd parity or spin two strongly disfavored.
Nothing news about this from CMS. What they have released doesn’t at all confirm the ATLAS mass difference, with them seeing the ZZ peak at 126.2 +/- .6 GeV, gamma gamma around 125. So their masses are compatible and in the middle between the two extreme ATLAS values.
All in all, still looking like a garden-variety SM Higgs. Next update with lots more data likely to be in March at Moriond.
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