Summer running at the LHC

The Large Hadron Collider (LHC) has delivered over twice as many collisions to the ATLAS and CMS experiments this year as it did in the whole of 2011

Last year, ATLAS and CMS each recorded a total of around 5.6 inverse femtobarns of data. This measure of accelerator performance is equivalent to about 560 trillion proton-proton collisions. On 3 August, the LHCb experiment passed the 1 inverse femtobarn mark (100 trillion proton collisions delivered) for this year; ATLAS and CMS passed 10 inverse femtobarns the following day. The LHC is well on its way to its goal of delivering in the order of 1500 trillion proton-proton collisions in 2012.

The LHC is operating at 1380 proton bunches per beam, the maximum value set for this year, with around 1.5 × 1011 protons in each bunch. The accelerator has also far exceeded the best instantaneous collision rate achieved last year: the maximum peak luminosity in 2011 was 3.6 × 1033 collisions per square centimetre per second; the most recent record 7.2 × 1033 cm-2 s-1.

The higher collision energy of 4 TeV per beam this year (compared to 3.5 TeV per beam in 2011) and the resulting higher number of collisions are expected to enhance the machine's discovery potential considerably, opening up further possibilities in the searches for new physics.

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