(The magnificent performance of the LHC has forced upward revision of data to achieve objectives in 2011)

After 180 days of operation and 400 trillion proton-proton collisions, the operating cycle of the LHC in 2011 came to an end at 17:15 pm on 30 October. In its second year of operation, the LHC team has exceeded its operational objectives, constantly increasing the speed at which the LHC has provided the data to the experiments.

At the beginning of the year, the goal for the LHC was to accumulate an amount of data that physicists call a reverse femtobarn during 2011. The first reverse femtobarn was reached June 17, leaving the LHC experiments in a good position ahead of the major scientific conferences and forcing Summer to revise the target upward to acquire data in 2011 to 5 femtobarns inverse . This milestone was achieved on 18 October, with a total for the year of nearly six femtobarns reverse delivered to each of the two major LHC experiments, ATLAS and CMS .

“At the end of the operating cycle with protons of the LHC this year has reached cruising speed,” said Accelerators and Technology Director of CERN , Steve Myers. “To put things in context, the current rate of production of data is a factor of 4 million more than in the first cycle of operation of 2010, and a factor of 30 higher than in early 2011.”

Among the physical milestones achieved in the LHC proton operation is to narrow the search for the Higgs boson andsupersymmetric particles , testing the Standard Model of particle physics increasingly tougher tests and advancing our understanding of the early universe.

“It was an important year and exciting for the scientific community at the LHC, especially for our students and post-docs from around the world. We have a large number of measurements of the Standard Model and agreed to uncharted territory in search of new physics. In particular, we have limited the mass of the Higgs particle to rank as light as possible, if it exists, “said Fabiola Gianotti ATLAS spokesperson. “This mass range is more difficult to study.”

“Looking back at this year’s fantastic, I have the impression of living in a kind of a dream,” said CMS spokesman Guido Tonelli.“We have produced dozens of new measures and significantly restricted the space available for new physics models, and the best is yet to come. Hundreds of young scientists are analyzing the huge amount of data accumulated so far, soon we will have new results and perhaps something important to say about the Higgs boson in the Standard Model. “

“We have the amount of data that we dreamed at the beginning of the year and the results are testing the Standard Model of particle physics through very tough test,” said spokesman LHCb Pierluigi Campana. “So far, the theory has withstood these tests with flying colors, but thanks to the superb performance of the LHC, we are reaching sensitivity levels that can see beyond the Standard Model. The researchers, especially young people, are experiencing a great enthusiastically waiting to find new physics “.

In the coming weeks, the LHC experiments will analyze all 2011 data. Thus, although it is possible that new physics arising from the analysis is also likely to be required for this inverse femtobarns the 10 originally planned for the period 2011-2012.

As in 2010 , the LHC is preparing to four weeks of operation with lead ion collisions, but with a new feature this year, the largest particle accelerator in the world trying to prove they can also be able to collide proton lead ions in two periods devoted to the development of the machine. If successful, these tests will lead to a new operating system of the LHC, using protons to study the internal structure of the ions much more massive lead.

This is important for the program operation with lead ions, which aims to study the so-called “ quark-gluon plasma , “the primordial soup of particles from which evolved the matter that makes up the visible universe.

“To collide lead ions allows us to produce and study small pieces of this primordial soup,” said spokeswoman Alice Giubellino Paolo, “but like any good cook would say, to understand a full recipe is vital to understand the ingredients, which is what that can facilitate the study of quark-gluon plasma. “

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