CERN Richard Jacobsson 1 Welcome to CERN!

CERN Richard Jacobsson 2 What is CERN? l European Organization for Nuclear Research, founded in 1954 l Currently 20 member countries

CERN Richard Jacobsson 3

CERN Richard Jacobsson 4 World laboratory l Model for international collaboration - 80 nations represented at CERN l 8000 scientists, in total about people are involved at CERN 2593 Staff 778 Fellows and Associates 7507 Users

CERN Richard Jacobsson 5 Mission l CERN’s objective is pure basic research in particle physics l 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

CERN Richard Jacobsson 6 What is particle physics? l Quest to understand: –Fundamental constituents of matter - Matter particles –Interactions with which particles act on each other - Interactions –Particles propagating the interactions - Messenger particles l Ultimately describe: –Birth of the Universe, the Big Bang –Passed and future Evolution l Strong link between the infinitely small (particle physics) and infinitely large (cosmology)

CERN Richard Jacobsson 7 Greeks (Empedocles) 500 BC Constituents of Matter

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

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

CERN Richard Jacobsson 10 Seeing Finer Structures m10 -6 m10 -9 m m m m Light microscope Electron microscope

CERN Richard Jacobsson 11 Seeing Finest Structures CERN Accelerator ~27 km! Resolution ~ m 1000 times smaller than a proton!! ? Proton

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

CERN Richard Jacobsson 13 CERN 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? 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?

CERN Richard Jacobsson 14 CERN Accelerator ~27 km! Temperature ~10 16 K : x!!! High Temperature

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

CERN Richard Jacobsson 16 LHCb CMS ATLAS ALICE

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

CERN Richard Jacobsson 18 General detector

CERN Richard Jacobsson 19

CERN Richard Jacobsson 20 How do we work? ExperimentalistsPhenomenologistsTheorists CERN Experiments: AcceleratorDetectorAnalyses Public awarenessTechnolog y Training