mardi 24 janvier 2012

LHC physics: More than just the Higgs search












CERN - European Organization for Nuclear Research logo.

Jan. 24, 2012


Events containing a muon pair and a photon detected by the ATLAS calorimeter. The three peaks are events consistent with different quarkonium decay states. The scale on the horizontal axis is mass. (Credit: ATLAS)

The LHC has been in the limelight recently with the first tantalizing hints concerning the Higgs boson. But there's more to physics at the LHC. Two of the LHC experiments have recently made discoveries in other areas of particle physics.

In November the LHCb experiment reported a new effect in the decays of particles containing a charm quark (or antiquark). The result could be the first evidence for CP violation  - a tiny difference in the behaviour of matter and antimatter - in charmed particles. The effect is very small, but more data should reveal whether it points to physics beyond the Standard Model.

 The ATLAS detector

Dimensions: 46 feet long, 25 meters wide, 25 feet high, ATLAS is the largest detector ever built.
  -   Weight: 7000 tons
  -   Configuration: Barrel and caps
  -   Location: Meyrin, Switzerland.

In December the ATLAS experiment announced the discovery of a new "quarkonium state", containing a beauty quark bound with its antiquark. Predicted by theory, it is known as the χb(3P). The new state will help in understanding the force that binds quarks (and antiquarks) together.

Watch out for more discoveries in 2012!

Note:

The European Organization for Nuclear Research (French: Organisation européenne pour la recherche nucléaire), known as CERN, is an international organization whose purpose is to operate the world's largest particle physics laboratory, which is situated in the northwest suburbs of Geneva on the Franco–Swiss border. Established in 1954, the organization has twenty European member states.

The term CERN is also used to refer to the laboratory itself, which employs just under 2400 full-time employees/workers, as well as some 7931 scientists and engineers representing 608 universities and research facilities and 113 nationalities.

find out more:

    LHCb website: http://lhcb-public.web.cern.ch/lhcb-public/

    Quantum diaries: Charm and beauty - LHCb has it all!: http://www.quantumdiaries.org/2011/11/18/charm-and-beauty-lhcb-has-it-all/

    ATLAS discovers its first new particle: http://www.atlas.ch/news/2011/ATLAS-discovers-its-first-new-particle.html

    Quantum diaries: New compostie particle discovered by ATLAS: http://www.quantumdiaries.org/2012/01/12/new-composite-particle-discovered-by-atlas/

Images, Text, Credit: CERN.

Cheers, Orbiter.ch