CERN

CERN, the European Organization for Nuclear Research,was founded in 1954. It has become a prime example ofinternational collaboration, with currently 20 Member States.It is the biggest particle physics laboratory in the world,and sits astride the Franco-Swiss border near Geneva.

Seeking answers to questions about the UniverseWhat is it made of?How did it come to be the way it is?

Uniting 7000 scientists from more than 80 countries,CERN is a laboratory for the world

Advancing the frontiers of technology and engineering

Training the young scientists and engineers who will bethe experts of tomorrow

European Organization for Nuclear Research

Atom

Electron

Nucleus

Proton

u

u d

Molecule

Matter

Neutron

Quarks

CERN is a laboratory where scientists unite to study the buildingblocks of matter and the forces that hold them together.

1957 1959

First accele

rator, th

e Synch

ro-

cyclotron(SC), be

gins op

eration

Proton

Synchrotro

n (PS)

beginsope

ration

Georges Ch

arpak inventsmultiwire

proportion

al cham

ber(NobelPrize 19

92)

Intersec

tingStorage Rings

(ISR)

start op

eration, the world

’s first

proton–proton co

llider

Super P

rot

beginsop

1968 1971 1973 1976

Discovery o

f “neutral c

urrents”

first

confirm

ation of the electr

oweak

theory

Further kinds of elementary particleexist in nature, for example incosmic rays. These are invisibleshowers of particles created whenenergetic particles from outer spacecrash into the Earth’s atmosphere.In all there are 12 types of particlethat form two groups – quarks andleptons (electron-like particles).

Different forces act between the particles. The strong force, theelectromagnetic force and gravity glue the particles together intobigger structures, from the invisibly small atoms to huge galaxies ofmillions of stars. The weak force changes particles and atoms fromone type to another, as in reactions that fuel the sun.The forces are themselves carried by particles that are different fromthe particles of matter. Force-carrying particles have only a fleetingexistence as they carry information from one matter particle toanother.

The basic building blocks are tinyparticles, much smaller even thanatoms. Four kinds of theseelementary particles are neededto account for all the matter wesee in the world around us. Theseare the up-quark, the down-quark,the electron and the electron-neutrino.

Forces

Carriers

Gravitational

Graviton (?)

Electromagnetic

Photon

Strong

Gluon

u

u d

Weak

W and Z bosons

tonSynchrotro

n (SPS)

peratio

n

Discovery o

f Wand

Z particles

. NobelPrize fo

r

Carlo R

ubbia andSim

onvan

derMee

r in1984

Accelerators use powerful electric fields to give energy tobeams of particles, and magnetic fields to guide the beamsthrough themachines. The bigger machines are circular and themagnetic fields are used to steer the particles round and rounda ring, so that they collect energy with each lap.

Physicists at CERN explore matter using machines called parti-cle accelerators. These accelerate beams of particles and smashthem into each other, or into other targets, to create high ener-gy conditions similar to those in the first instants of theUniverse.

CERN is currently building its most powerful machine ever, theLarge Hadron Collider, or LHC. This machine is being installed ina tunnel 27 km in circumference which housed a previousmachine, the Large Electron Positron collider, LEP. By studyingcollisions at higher energies than ever before, physicistsworking with the LHC will make further progress inunderstanding the mysteries of how our Universe is made andhow it came to be.

Detectors record what happens when the particles collide. Theenergetic collisions produce many new particles, as energyturns into matter in accordance with Einstein’s equation, E=mc2,where E stands for energy, m for mass and c is the speed oflight.

The different layers of a detector measure different propertiesof the particles produced in collisions. Tracking devices revealthe paths of the particles as they fly away from the collision.Other layers, called calorimeters, measure the energy of theparticles. A magnet built into the detector bends the paths ofelectrically charged particles and helps in identifying theparticle types.

1983 1989

Large Electr

onPositron co

llider (LE

P) starts

operation;confirm

s existence

of only3 ne

utrinos

1990 1995

TimBerners-Le

e invents th

eWorld

WideWeb

First ob

servatio

n of an

tihydrogen

1993

Precise

results o

n CP violat

ion, a tiny

difference

betwee

n matte

r and an

timatte

r

CERN’s research at the frontiers of science also pushesback the boundaries of technology. The results, inareas from computing to materials science, can havemuch broader applications.

CERN also produces beamsof antiparticles, which arethe constituents of antimatter– a kind of “mirror image” ofordinary matter. There arenow several experiments atCERN making and studyingantimatter.

CERN delivers a variety ofbeams including high energymuons to study the structureof the proton, heavy ions toform new states of matter, andradioactive ion beams toobserve exotic nuclei.

Beams of neutrinos have beenimportant throughout thehistory of CERN. The latestventure is to send a beam ofthese very weakly interactingparticles under the Earth’ssurface to the Gran SassoLaboratory in Italy, 730 km away.

TheWorldWideWebwas invented atCERN to help particle physicistsaround the world to communicate.Now CERN is leading work to createa “computing Grid” that will harnessvast amounts of computer powerthrough networks across the world.

Particle detectors invented at CERNare used in techniques for medicaldiagnosis.

Engineering for CERN,especially in cryogenics,superconductivity, vacuum,microelectronics and civilengineering, gives companiesexperience that they can applyelsewhere.

CERN is the world’s largest centre for research in particle physics, with severalinterlinked accelerators that provide many kinds of particle for many differentexperiments.

2002

CERNEuropean Organization forNuclear ResearchCH-1211 Geneva, Switzerlandwww.cern.ch

Education and Communication GroupMarch 2008CERN-Brochure-2008-002-Eng

First results on

antihyd

rogen a

toms

2008

LHCplan

nedstar

t-up

2000

Creatio

n of a n

ewstate of

matter,qua

rk–gluon plasm

a,

which p

robably

existed

justafte

r the Big Bang

.

Constru

ction of Large

Hadron

Collider (LH

C) begin

s

1999