1. Welcome to CERN!

2. What is CERN?
European Organization for Nuclear Research, founded in 1954
Currently 20 member countries
It’s my pleasure to give you an introduction to CERN. In 15 minutes I will tell you a little bit about what
CERN is, what we do at CERN and how we do it. This will hopefully also give you an overview of
the things that you will hear and see during your visit. My presentation will surely generate plenty
of questions and you will have plenty of opportunities to ask these questions during the day.
So what is CERN? CERN is the European Organization for Nuclear Research or better in french Conseil
Europeen pour la Recherche Nucleaire. It was founded in 1954 with the aim of gathering Europe’s
scientist under one roof to start up serious scientific European wide collaboration, something which of
course had been practically stopped by the second World War. 12 European countries joined up and
became CERNs first members. Over the years CERN has expanded and today includes 20 European
member countries.

4. World laboratory
Model for international collaboration - 80 nations represented at CERN
6500 scientists, in total about people are involved at CERN
However, CERN is more than European, the initial ambition was already to make CERN a world
laboratory. Although CERN remains by constitution a European laboratory, CERN has today
visiting researchers from 60 countries outside Europe as you can see from this map.
In total there are about people involved in the projects at CERN, out of which 6500 are
scientists. Only of these are actually employed by CERN. The power of CERN is that
most of its scientists are travelling back and forth between their home institutes and CERN.
This means that they can spread the knowledge and the technologies of CERN in their contact
with national industry, in teaching and to public.

5. Mission CERN’s objective is pure basic research in particle physics
However, results and spin-offs are of four major kinds:
- Progress in particle physics
- Developing tomorrow’s technology
- Training of tomorrow’s scientists and engineers
- Informing and stimulating the public

6. What is particle physics?
Quest to understand:
Fundamental constituents of matter - Matter particles
Interactions with which particles act on each other - Interactions
Particles propagating the interactions - Messenger particles
Ultimately describe:
Birth of the Universe, the Big Bang
Passed and future Evolution
Particle physics is about answering the very same questions man asked himself
as soon as he gained his self-consciousness. How did we come into existence
and why are things like they are? We have made some progress in the methods
used to answer these questions and today the quest to understand these
questions is focused on:
Strong link between the infinitely small (particle physics)
and infinitely large (cosmology)

7. Constituents of Matter
Greeks (Empedocles) 500 BC

8. Constituents of Matter
Periodic table (Mendeleev) ~1870
Eightfold Way (Gell-Mann) ~1960
Electron, proton, neutron

9. Constituents of Matter
Quarks (Gell-Mann) 1964
Proton
Today’s periodic system of the fundamental building blocks

10. Seeing Finer Structures
10-1m
10-6m
10-9m
10-12m
10-15m
10-18m
Electron microscope
Light microscope

11. Seeing Finest Structures
CERN Accelerator ~27 km!
Resolution ~10-18 m times smaller than a proton!! ?
Proton
- With the LHC we will improve on this by a factor of 10

12. Interactions Energy = Temperature Time Electricity Magnetism Light
Terrestrial
Gravity
Planetary
Electromagnetism
Maxwell’s
Electromagnetism
Newton’s
Gravitation
Energy = Temperature
General
Relativity
Radioactivity
Atomic nuclei
Quantum
Electrodynamics
Weak nuclear
force
Strong force
Super Unified
Theory
Time
Electroweak
force
“Standard Model”
Grand Unified
Theory

13. What do we not know? What do we know?
How did the forces and the particles behave
in the very beginning?
Why does Nature have a preference for matter over antimatter?
What caused the small density variations that seeded galaxies?
How did the particles acquire their masses?
In which way were the protons, the neutrons,
and their relatives formed?
Under which conditions were the nuclei formed?
What is 96% of the Universe made of
- the Dark Matter and the Dark Energy?
What do we not know?
The Universe begun as an extremely hot
and dense soup of energy and particles
The rapidly expanding Universe is already endowed
with an excess of matter over antimatter by one in a billion
and small density variations
The soup of quarks condenses into protons, neutrons,..
The first light nuclei are formed
Atoms are formed
This marks the limit between the use of telescopes
and accelerators!
Recent research shows that we only know
what 4% of the Universe is and that its
expansion is accelerating
What do we know?
CERN
Let’s take a look at what we do know about the Universe.
The cone is supposed to represent the expansion of the Universe and shows
four different stages during its evolution from the beginning until today 13.7
billion years later.
The fact that the Universe have a beginning was already very hard to swallow
50 years ago but since then we have found out many similar surprises.
Thus, the Universe started out as a hot and extremely dense soup of energy and particles.
As it expands it
So all this understanding is often summarized in what we call the standard
model of particle physics and cosmology.
Now let’s take a look at those particular questions that we are in fact attacking
with the next project at CERN.
First of all we would like to know how the particles and the forces behaved
in the very beginning to understand how they decided the course of the
Universe, so it would be good if we could recreate these conditions.
Not long after the beginning, only a 10th of a billionth of a second.

14. High Temperature CERN Accelerator ~27 km! Temperature ~1016 K :x
!!!
The energy in the LHC collisions corresponds to a temperature of 1000 million TIMES the temperature in the center of the sun, which is about million degrees
We look at a corner of the Big Bang

15. How to find out?
Large Hadron Collider (LHC) is a 27 km long particle collider
Recreate conditions at “small scale”:
Temperature 1016 K that is x
second after Big Bang

16. CMS
ALICE
ATLAS
LHCb

17. How to find out? cont’d
Four experiments – detectors – record the particle collisions
ALICE
ATLAS
CMS
LHCb

18. General detector

20. How do we work? Experimentalists Phenomenologists Theorists
CERN Experiments:
Accelerator
Detector
Analyses
Just about every type of scientist and engineer you can name is involved in the construction of the CERN experiments.
Varying career. The idea is to be mobile in the career, not become just an expert. It’s the learning phase that allows you to look at a problem from new angles. Out of 10 questions, 9 are stupid ideas due to inexperience but that 10th is a grain of gold which makes science and technology jump forward.
Working in fundamental science, in particular particle physics, puts you in contact with physics, math, electronics, engineering, instrumentation and computing at the frontier of knowledge
In a society where even the educational interface between scientists and public, the media, is corrupt by commercial and political pressure, fundamental science is also about spending a part of your time reaching the public directly and devising strategies to improve on general education!
Technology
Public awareness
Training