Another milestone has been passed in the long run of ATLAS toward new physics. On Monday August 9, 2010 ATLAS has recorded the first inverse picobarn (pb-1) of 7 TeV collisions. The trend is good and we recently reached the 0.1 pb-1 per day of integrated luminosity (meaning that we can now collect in ~10 days the amount of data we have collected over the last 4 months).
ATLAS has been designed to detect rare events in high energy proton-proton collisions. ATLAS ultimate goal is to measure events as rare as one in several thousand billions, but we are modest (for the time being) waiting for the luminosity to rise.
After ramping of the beams to 3.5 TeV and tuning, final checks, and some emotions due to an unforeseen beam dump, the 7 TeV collisions finally appeared on the on-line monitors of the ATLAS Control Room.
Last night a new very important milestone has been reached by the LHC: two counter-circulating proton beams have been accelerated for the first time to 3.5 TeV, the energy that they should routinely reach in the 2010-2011 running period.
On Sunday December 6, 2009 at 8.00 the ATLAS Pixel Detector has measured, for the first time, tracks emerging from LHC collisions. It has been a very smooth start.