By combining their data ATLAS and CMS increase their sensitivity in the Higgs boson search

At 17:00 on Sunday 30th October the LHC dumped the last proton beams
for the year to start the machine development period
and to prepare for heavy ion running. This means that we have
come to the end of proton operation for 2011.

Grab a can of soda, shake it thoroughly, and open it up. What do you get? It’s an explosion of fizz. A similar phenomenon in the subatomic world might help us probe the nature of fundamental particles.

The LHC has now delivered 5 inverse femtobarns (fb⁻¹) of data in 2011, of which CMS has collected 4.53 fb⁻¹.

This year, for the first time, the winners of the Italian Physics, Mathematics and Informatics Olympiads received an unforgettable reward from the Italian Ministry of Education, University and Research (MIUR): a trip to CERN.

You have to be curious and creative to work for a project like CMS. Without these qualities, it would be impossible to build an instrument of its complexity. The CMS detector is a marvellous instrument at the forefront of technology and will open windows into 21^st century science.

On Friday 7^th October the LHC delivered, for the first time in the history of High Energy Physics, proton-proton collisions at the design frequency of 40 MHz, with bunches of protons colliding every 25 nanoseconds (ns), doubling the frequency achieved so far.

Three researchers behind the discovery that our Universe's expansion is accelerating have been awarded this year's Nobel prize for physics. Saul Perlmutter and Adam Riess of the US and Brian Schmidt of Australia will divide the prize. [...]

Watch the very first TV episode of "What's new @ CERN" featuring CMS physicist Yves Sirois, John Ellis and other physicists talking about the Higgs Boson, the Standard Model, Supersymmetry and neutrinos. "What's new @ CERN" is a new monthly outreach TV programme produced by CERN.

The LHC has now delivered over 4 inverse femtobarns (fb⁻¹) of data in 2011, of which CMS has collected 3.7 fb⁻¹.

The international physics masterclasses allow high-school students to spend a day at a research institute and analyse real data from high-energy physics experiments.

Next short Technical Stop will take place from Monday the 7th to Friday the 11th of November 2011

On the evening of 23rd September CMS welcomed, for the second successive year, young local students to point 5 for an experience they will never forget - and this time we joined forces with TOTEM.

Read the paper: EXO-11-005

Once upon a time, the only thing that traveled faster than the speed of light was gossip.

Thanks to the Internet, the whole physics world was watching on Friday when Dario Autiero, of the Institut de Physique Nucléaire de Lyon in France, in front of a palpably skeptical roomful of physicists, put a whole new category of speed demons on the table, namely the shadowy subatomic particles known as neutrinos.

Over the course of 16.5 hours ending Wednesday, Sept. 14, the CMS experiment recorded 113.4 inverse picobarns of data, more than three times the 36 inverse picobarns it recorded in all of 2010. The detector's data-taking efficiency was impressively high.

CERN was a special guest this year at the famous Ars Electronica festival in Linz, Austria. The theme of this year’s festival 'Origin — how it all begins' relates to the diverse research carried out at CERN.

The Top quark is the heaviest of the six quarks of the Standard Model and was discovered only 16 years ago by the Tevatron experiments at Fermilab.

Read the paper: SUS-11-003

The analysis shows no excess of events over the Standard Model expectations. As a result, exclusion limits were placed on searches for squarks and gluinos in the Constrained Minimal Supersymmetric extension of the Standard Model (CMSSM).

It is well known that CERN is an open laboratory, welcoming visitors from around the world on a daily basis. Often these visits are organised by schools or colleges, or are simply part of a family vacation to the Geneva area.

The latest results from the Large Hadron Collider serve as a reality check for expectations that radical scientific discoveries are just around the corner. A month ago, folks were buzzing about prospects that the elusive Higgs boson might soon be found.

The Higgs boson, the most sought-after particle in all of physics, is proving tougher to find than physicists had hoped. [...]

The Higgs boson is the only particle predicted by the Standard Model that has not yet been seen by experiments. It helps explain how elementary particles acquire mass. If the Higgs boson exists it will be produced in proton-proton collisions at the LHC.

Scientists at the Large Hadron Collider say a signal that suggested they might have seen "hints" of the long-sought Higgs boson particle has weakened. [...]

Ripples of excitement swept through the physics community last month when Cern scientists reported what looked like glimpses of the long-sought Higgs boson. But the hopes have been dashed as it was revealed that the tantalising hints had all but faded away. [ ... ]

Read the paper: TOP-11-003

The measured production rates of Top-antiTop pairs, where one lepton and four jets of particles is observed in the final state, show good agreement with Quantum Chromodynamics (QCD), the theory of the strong interaction.

The number of events that an experiment observes is proportional to a quantity called the luminosity — a measure of how many collisions are occurring in the detector.

This year's HCAL test beam run in July was completely devoted to studies of hardware that will be used in the upcoming upgrades. During the course of the two weeks the detector was moved in two independent setups – HF and the combined EB+HB+HO – into various positions relative to the beam.