Large Hadron Collider proton run for 2011 reaches successful conclusion

Oct 31, 2011
LHC control screen displaying the dump of the last beams for the LHC's 2011 proton run. The image on the right shows the cross section of the beam just before it was stopped. Credit: CERN

(PhysOrg.com) -- After some 180 days of running and four hundred trillion (4x1014) proton proton collisions, the LHC’s 2011 proton run came to an end at 5.15pm yesterday evening. For the second year running, the LHC team has largely surpassed its operational objectives, steadily increasing the rate at which the LHC has delivered data to the experiments.

At the beginning of the year’s run, the objective for the was to deliver a quantity of data known to physicists as one inverse femtobarn during the course of 2011. The first inverse femtobarn came on 17 June, setting the experiments up well for the major physics conferences of the summer and requiring the 2011 data objective to be revised upwards to five inverse femtobarns. That milestone was passed by 18 October, with the grand total for the year being almost six inverse femtobarns delivered to each of the two general-purpose experiments ATLAS and CMS.

“At the end of this year’s proton running, the LHC is reaching cruising speed,” said CERN’s Director for Accelerators and Technology, Steve Myers. “To put things in context, the present data production rate is a factor of 4 million higher than in the first run in 2010 and a factor of 30 higher than at the beginning of 2011.”

Physics highlights from this year’s proton running include closing down the space available for the long sought Higgs and supersymmetric particles to hide in, putting the Standard Model of particle physics through increasingly gruelling tests, and advancing our understanding of the primordial universe.

“It has been a remarkable and exciting year for the whole LHC scientific community, in particular for our students and post-docs from all over the world. We have made a huge number of measurements of the Standard Model and accessed unexplored territory in searches for new physics. In particular, we have constrained the Higgs particle to the light end of its possible mass range, if it exists at all,” said ATLAS Spokesperson Fabiola Gianotti. “This is where both theory and experimental data expected it would be, but it’s the hardest mass range to study.”

“Looking back at this fantastic year I have the impression of living in a sort of a dream,” said CMS Spokesperson Guido Tonelli. “We have produced tens of new measurements and constrained significantly the space available for models of new physics and the best is still to come. As we speak hundreds of young scientists are still analysing the huge amount of data accumulated so far; we’ll soon have new results and, maybe, something important to say on the Standard Model Higgs Boson.”

“We’ve got from the LHC the amount of data we dreamt of at the beginning of the year and our results are putting the Standard Model of particle physics through a very tough test ” said LHCb Spokesperson Pierluigi Campana. “So far, it has come through with flying colours, but thanks to the great performance of the LHC, we are reaching levels of sensitivity where we can see beyond the . The researchers, especially the young ones, are experiencing great excitement, looking forward to new physics.”

Over the coming days and weeks, the LHC experiments will be analysing the full 2011 data set to home in further on new physics. However, while it is possible that new physics may emerge, it is equally likely that the full 10 inverse femtobarns initially foreseen for 2011 and 2012 will be required.

As in 2010, the LHC is now being prepared for four weeks of lead-ion running, but in a new development this year, the world’s largest particle accelerator will also attempt to demonstrate that large can also be agile by colliding protons with lead ions in two dedicated periods of machine development. If successful, these tests will lead to a new strand of LHC operation, using protons to probe the internal structure of the much more massive lead ions.

This is important for the lead-ion programme, whose goal is to study quark-gluon plasma, the primordial soup of particles from which the ordinary matter of today’s visible universe evolved.

“Smashing lead ions together allows us to produce and study tiny pieces of primordial soup,” said ALICE Spokesperson Paolo Giubellino, “but as any good cook will tell you, to understand a recipe fully, it’s vital to understand the ingredients, and in the case of quark-gluon plasma, this is what proton-lead ion collisions could bring.”

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User comments : 11

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fmfbrestel
5 / 5 (1) Oct 31, 2011
....And it still hasn't destroyed the world.

Nice timing though physorg, troll baiting for LHC apocalypse banter on Halloween?
pauljpease
not rated yet Oct 31, 2011
....And it still hasn't destroyed the world.

Nice timing though physorg, troll baiting for LHC apocalypse banter on Halloween?


Not unless it was a conspiracy initiated by the scientists at the LHC, since the article is about how it just finished its run YESTERDAY....
mattytheory
not rated yet Oct 31, 2011
Callippo
1 / 5 (2) Oct 31, 2011
It still runs at much lower power, than it was projected.
Eric_B
2.6 / 5 (7) Oct 31, 2011
They really aren't running the LHC. The data is fake! That is why...NO HIGGS! Not because it isn't there but because they can't make a statement about it.
U would have to be stupid to think we could go to the moon and back to believe it's real. The moon is a one way trip. The people that live there do not allow interlopers to leave.

(I'll tell you what they use them for laayyyter!)

The LHC WILL DESTROY THE WORLD, if necessary. That is what it was built to do!

Once the Elites have fled the Arab Spring and OWS and the realization that Global Warming is really Global Cooling and their tropiinvestment resorts will be going bankrupt, they will flee Earth for their MCMoon Mansions and Cushy Crater Condos and in unison, shout back to us, "You suck!", they push the button initiating the creation of the hungry, mini-black hole that WILL DEVOUR THE EARTH!
We will all spend eternity as Flesh-Eating Dark Matter Zombies until light from Venus refracting off space-swampgas...too late!
Royale
not rated yet Nov 01, 2011
Eric, You never let on to the fact you were making #insaneproclamations it was a pretty funny read though, thanks for that.
Ricochet
not rated yet Nov 01, 2011
I don't think the point is neccesarily that the LHC is running at its top power level... But that it's running at the appropriate power level for the current experiment.
If they put too much power into smashing some elements, they'll either make it fail, or they'll produce data too fast for the storage devices to keep up with.
Eric_B
not rated yet Nov 02, 2011
thank you, thank you... [takes a bow]
Ricochet
not rated yet Nov 02, 2011
Yes, I must admit it took me a bit to recognize that it wasn't a serious rant, and I was very much relieved to realize that it was humor. Good job, Eric!
rawa1
1 / 5 (1) Nov 04, 2011
Large Hadron Collider proton run for 2011 reaches successful conclusion
Yep, it successfully disproved most of theoretical models by now: Higgs boson of Standard Model, supersymmetry and string theory, not to say about dozens of phenomenological models.
Ricochet
not rated yet Nov 05, 2011
Large Hadron Collider proton run for 2011 reaches successful conclusion
Yep, it successfully disproved most of theoretical models by now: Higgs boson of Standard Model, supersymmetry and string theory, not to say about dozens of phenomenological models.

You're missing a pretty sizeable bandgap that hasn't been explored yet.