- As everyone knows, the luminosity collected by ATLAS and CMS just passed the 1 fb-1 benchmark which had originally been the goal for the entire 2011. The LHC management is running a policy of making careful projections which can later be spectacularly surpassed. We all agree it's better than the previous policy of bold projections and spectacular catastrophes.
- Unofficial predictions for the luminosity at the end of 2011 are Gaussian distributed with a peak around 5 fb-1. It means that, this year we'll probably learn whether the Standard Model Higgs exists or not! That's massive.
- Several results using a good chunk of this year's data, around 200 pb-1, have already emerged from ATLAS on the occasion of the PLHC conference in Perugia 2 weeks ago. The most interesting result is the t-tbar invariant mass spectrum. The most disappointing, too. If Tevatron's excess in the top quark forward-backward asymmetry is due to a 1-2 TeV heavy Kaluza-Klein gluon the t-tbar spectrum should display a peak or an excess at the tail. Alas, nothing there, as you can see.
- About the update on searches for Z' decaying to leptons, see Tommaso's blog. There's also a new search for W' in the muon + missing energy channel. In those cases also nothing, only vague rumors.
- Meanwhile SUSY searches are continuing at full steam. New analyses in the jets+met and jets+lepton+met channels are out. From the plot you can read that, for equal squark and gluino masses, the limit on the masses is above the magic threshold of 1 TeV. If the squarks are decoupled the limit on the gluino mass is slightly less stringent, about 750 GeV, and similalry the other way around. Children take about 6 years to realize Santa Claus does not exist, the LHC may be quicker than that.
- Theorists, on the other hand, are trying to understand the deeper meaning of the LHC limits on SUSY. The conclusion is that SUSY must be just behind the corner, just a little bit more, one last effort, and we'll see it. One should note that preference of the global fits for light superparticle masses is driven by one measurement: the long standing 3 sigma excess in the muon anomalous magnetic moment. Interestingly, a recent paper reevaluates the theoretical contributions to the muon g-2 and concludes there is no excess whatsoever. I am not in a position to judge whether the paper is correct, drop your comment if you are.
- Meanwhile, ATLAS and CMS keep posting papers on arXiv which use only the meager last year's harvest of 35pb-1. At this point it feels like offering ZX Spectrum in an Apple store.
Monday, 20 June 2011
Meanwhile at the LHC
The excitement about the CDF bump is subsiding so we can relax and look back at the LHC. A lot is going on there, although the best of the action will occur later this summer.