Latest from the LHC

CMS and ATLAS have just released final versions of their Higgs analyses for the 2011 data (the new CMS gamma-gamma analysis was previously discussed here). The preliminary versions of these were what was released last December, and the final versions don’t differ in a major way. The bottom line is still the same: there’s evidence for a Higgs around 125 GeV, of the sort that you would expect with this amount of data if it were really there, but the evidence is still too weak to claim discovery. The CMS papers are here, here and here, with the combination here. The ATLAS papers are here and here, combination here.
Check out Philip Gibbs to see if he updates his unofficial overall combination. Rumor is that the official CMS+ATLAS combination, along with the latest Tevatron Higgs results, will be released at Moriond (first week of March).

This week the people responsible for operating the LHC machine are meeting at Chamonix, slides here. Current plans are to start recommissioning the machine March 14, and run at 4 TeV/beam, a slight increase over the previous 3.5 TeV/beam. Projected integrated luminosity is 3-4 times that of 2011 (15-20 inverse femtobarns). After the end of the pp run in October, it will be quite a long time until proton collisions start up again (late 2014 or 2015?), since there will be a long shutdown to fix magnet interconnections and allow the machine to operate at or near design energy (7 TeV/beam).

On some other blogs you can find rumors of evidence for observation of an stop squark. I’ve heard nothing of the sort, but who knows? Informed rumors are encouraged. One of the things about the LHC results that has surprised me is the lack of any such claims over the past year or so. With all the searches being done, you’d think that someone, somewhere would find a fluctuation big enough to get SUSY enthusiasts excited, whether or not there was anything actually there.

Update: For more about this, see Tommaso Dorigo, Matt Strassler and Jester.

Update: A new unofficial combination from Philip Gibbs is now up here.

Update: Chamonix summary is here. The long shutdown starting this fall should last until at least September 2014. After this the hope is to run the machine at 6.5 TeV/beam. There seems to be little hope any longer of running at full design energy of 7 TeV/beam.

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6 Responses to Latest from the LHC

  1. Pingback: Se refuerza la seƱal del Higgs observada en ATLAS y CMS del LHC en el CERN « Francis (th)E mule Science's News

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  3. Bernhard says:

    So, we will probably discover the Higgs this year and if nothing else shows up, be until 2015 without data again and still having absolutely no good idea what lies beyond the Standard Model. After the Higgs hangover passes, will be a depressing scenario.

  4. neo says:

    re “he long shutdown starting this fall should last until at least September 2014. After this the hope is to run the machine at 6.5 TeV/beam. There seems to be little hope any longer of running at full design energy of 7 TeV/beam.”

    What are the ramifications to BSM physics for this?

  5. Peter Woit says:

    neo,

    The implications of the lower energy are not that large. Shouldn’t significantly affect the study of the Higgs (if it really is around 125 GeV). The bounds on SUSY and other exotic BSM phenomena will be slightly weaker, but that’s not of great significance for physics.

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