The Large Hadron Collider has delivered 2 inverse femtobarns of integrated luminosity to ATLAS. This means that the experiments now have nearly twice the amounts of data used at the recent EPS-HEP conference in Grenoble. The additional statistics this provides would make significant advance in the search for the Higgs boson.
In the recent results the collaborations working on the CMS and ATLAS detectors saw tantalising hints of an excess at around 140 GeV indicating the possible presence of the long sought after boson, but the signal was not entirely consistent with the standard model expectations or the electroweak fits. A low mass Higgs multiplet may be a better match. At the Lepton-Photon conference in Mumbai this month they will show the full combination of the data analysed so far, with the likelihood that it will strengthen the signal seen separately by the two experiments.
To get a better handle on what they are really seeing they will need to add more data but we do not yet know when they will produce a new update with more than 2/fb per experiment. This would be enough to make a significant difference.
As ATLAS passes the 2/fb mark for integrated luminosity delivered over 2010 and 2011, this is just the beginning of a series of 2/fb milestones because not everyone agrees which figure is most significant. The detectors only record 90% to 95% of the data delivered and some people disregard the 48/pb delivered in 2010. The recorded luminosity for ATLAS in 2011 is around 1.9/fb but CMS has fallen behind with now only 1.75/fb recorded. Over the next few days all the figures will pass 2/fb but at viXra we like to start the celebrations as early as possible.
Update 6-Aug-2011: A record run lasting 26 hours has delivered over 100/pb to ATLAS and just slightly less to CMS. This takes ATLAS to over 2/pb recorded including 2010 and 2011 data. We have seen 370/pb delivered in just 5 days. In April I predicted that they would reach 70/pb per day. It has taken two months longer than I thought but they got there and still have the potential to go higher.
With this rate of delivery they should be able to reach 3/fb before start of the next break for development and maintenance on the 24th August. Can they still get 10/fb this year? It would require doubling the luminosity for the whole of last eight week run after the stop. That’s a stretch but not quite impossible.