Nuclear Science Symposium
and
Medical Imaging Conference

Lyon, France
October
15-20, 2000

CERN visit

Overview of this exceptional laboratory

CERN is a world leading particle physics research center, attracting scientists of over 80 nationalities. The laboratory mission is pure science but the tools of the trade are particle accelerators and detectors requiring leading edge technologies such as magnets, vacuum systems, and computing. With an annual budget in excess of 850 million Swiss Francs (1997 values), CERN is a major player in the business technology.
The LEP collider
On the summer of 1989, a large electron positron collider was switched on. Four detectors, ALEPH, DELPHI, L3 and OPAL surround the collision.
For 6 years its job was to produce Z particles, discovered in a Nobel prize winning CERN experiment (UA1) in 1983, which are carriers of one of the nature's fundamental forces.
In 1995, LEP's Z era came to end, and the machine moved up to 190 GeV. Known as LEP2, this second phase, which will end up in September 2000, produces and studies W particles, companions of the Z. People are also checking news ideas as supersymetry (SUSY) which is a new way of linking particles and the forces between them.
The LHC project

For a few years now, people have begun to work in parallel on new accelerator which will probe deeper into the matter. This Large Hadron Collider (LHC) will collide in 2005 beams of protons at an energy of 14 TeV.
The purpose of this new challenge is to try to answer to several questions that are for the moment unresolved by the Standard Model (which however has demonstrated that his predictions are in a superb agreement of what has been discovered at LEP for example).
Four huge experiments are under development for this study, each dedicated to a specific goal : ATLAS , CMS, LHCb and ALICE.

The scientists of ATLAS and CMS will be searching for discoveries that could explain the masses of quarks and leptons. The Standard Model explains this by proposing that mass is due to a new field called the Higgs field. This way of understanding leads to the predicted existence of a new particle, the Higgs boson which, if it exists, will be accessible to the LHC.
Their purpose is also to check a number of proposed theories that go beyond the Standard Model (Grand Unified Theory, SUper SYmmetry, ...) which could explain the remaining mystery.
Although their goal are essentially the same ATLAS and CMS have chosen different detector technologies to achieve it.

LHCb, has been optimized to study the B meson physics. Indeed, since the Standard Model does not predict exactly how much CP-violation there should be in B meson decays, it has to be measured. The final aim of this study is to try to explain why this apparent antimatter imbalance arises.
We want to find out exactly why nature has always treated matter and anti-matter differently, allowing our universe to exist ...

Finally ALICE is a is a Ion Collider experiment. His goal is to create a Quark Gluon Plasma (QGP) to understand the state the first moments of the universe (QGP was the state of the matter 15 billions years ago). To do so, they smash ions -atoms stripped of electrons- into each other at very high energy, squeezing the protons and neutrons to try to make them melt.

The visit

For the moment we don't have the details of the program because we don't know what will be accessible in October but we will inform you as soon as possible.

Bugey Nuclear Power Plant visit

On Thurday October 19th  9am-1pm (15 euro)