The invisible world The elementary particles Study Natures

The invisible world The elementary particles

Study Nature’s phenomena… Look for the hidden laws behind these phenomena…

Experiment beyond our senses…

Scale factors • Length (meters) 10 -15 m = size of atom’s nucleus 1 m = you 4. 10+16 m = distance that separate us from the star Alpha Centauri (4 light-years) • Time (seconds) 10 -23 s = lifetime of particle Z 0 1 s = you 10+17 s = sun’s lifetime • Energies (Joules) 10 -19 J = energy of a photon emitted by a lamp 10 -7 J = landing of a mosquito 10+9 J = your meals during the day 10+16 J = atomic bomb of 1 Megaton 10+26 J = light energy from the sun…every second!

Lets enter the invisible world 10 meters A rose tree

Lets enter the invisible world 0. 1 meter = 10 cm A fly on a rose tree leaf

Lets enter the invisible world 10 -3 meter = 1 mm The eye of a fly

Detectors of the invisible The optical microscope Onions cells 10 micron

Lets enter the invisible world 10 -5 meter = 10 microns A hair on the eye of a fly

Detectors of the invisible The electronic microscope First electronic microscope : E. Ruska and M. Knoll , 1932 (Nobel prize 1986) l= h / p l = longueur d’onde h = constante de Planck p = impulsion de la particule = mv Chloroplast within a plant cell Optical microscope Electronic microscope Light beam Electrons beam Optical lenses Electromagnetic lenses resolution 0. 5 micrometer resolution 0. 0002 micrometer 0. 1 micron

Lets enter the invisible world 10 -7 meter = 0. 1 micron The base of the hair and cells that make the eye of the fly

A few examples of scales The small… You need the same number of cells to make a human being as stars to make a galaxy (100 billions)

Lets enter the invisible world 10 -8 meter ~ 100 Angströms A DNA strand within the nucleus of a cell

Detectors of the invisible First scanning tunneling microscope: G. Binnig et H. Rohrer in 1981 (IBM, Zürich), Nobel prize 1986 Scanning tunneling microscope (STM) In 1990. the scanning tunneling microscope allowed researchers working at IBM to write the first letters in history written using nanotechnologies by placing 35 xenon atoms on a nickel surface. Voir aussi: http: //www. cndp. fr/themadoc/micro 3/rep_mcp. htm

Lets enter the invisible world 10 -10 meter = 1 Angström A carbon atom. It is one of the element that makes a molecule found in DNA Gold atoms deposited on a layer of carbon

A few examples of scales The very small… You need as many atoms to make an orange as oranges to fill the Earth

Lets enter the invisible world 10 -14 meter = 10 fermis The nucleus of a carbon atom (drawing)

A few examples of scales The very small… You need as many atom’s nucleus to fill an atom as oranges to cover France entirely… 15 times!

Detectors of the invisible Experiment ALEPH, at CERN

Lets enter the invisible world 10 -15 meter = 1 fermi A proton in the nucleus (drawing) A proton contains 3 quarks

Lets enter the invisible world

At the end of the invisible world Nuclear physics and particle physics

Elementary particles known in 2006

Forces Strong interaction gluon quark 10 -14 m quark

Forces Electromagnetic interaction photon electron Billions of km quark

Forces Weak interaction W+ neutrino 10 -14 m quark n → p + e - + ne W+ W- Z 0

Unification of the interactions Unification of the 3 interactions: electromagnetic, weak and strong Weak interaction + electromagnetic interaction = electroweak interaction (1967 -1973) Glashow, Salam, Weinberg Need Higgs 102 1015 1010 1 Ge. V = 1. 6 1010 Joules Ge. V

Forces Gravitation interaction graviton electron quark Billions of km

Lets summarize: Matter and forces… http: //www. diffusion. ens. fr/vip/table. G 00. html

…and the anti-matter 1928 : P. Dirac predicts the existence of antimatter Anti-electron trace in a C. Anderson bubble chamber 1932: C. Anderson discovers the anti-electron Collision between a electron and an anti-electron 1993: the LEP at CERN

…anti-matter (2) A A B B C(A) C(B) CPT(A) CPT(B) CP(A) CP(B) Three fundamental transformations: P: parity inversion C: matter anti-matter T: time reversal http: //ppd. fnal. gov/experiments/e 871/public/phys_slides. html

…anti-matter (3) P C CP Escher

…anti-matter (4) • Symmetry violated: P parity Right ≠ Left • Are there any other symmetries violated? Symmetry C matter ↔ anti-matter ? Left Right

…anti-matter (5) Cosmic microwave background has been measured Today in our universe • Diffuse cosmic background • First nucleosynthesis models • Number of stars This ratio was though to be in the past At the beginning, for 1 billion anti-matter particles, One condition: there must have been 1 billion and 3 matter particles CP violation

…anti-matter (6) The search for cosmic anti-matter To observe anti-matter in space, we « only » need sending a magnet Cosmic ray matter Anti-matter we can count cosmic rays and classify them by types The experiment AMS (Alpha Magnetic Spectrometer) was conceived to observe anti-matter in space

…Anti-matter (7) A simple magnet is not enough, we also need a particle physics detector ATLAS for the LHC • More than 7000 t • 44 m x 20 m • Power consumption > MW • Immobilised 100 m under ground AMS 02 Space constraints • Mass < 7 t • 3 mx 3 m • Power consumption < 2 k. W • Resistance : • Temperature -50° / +50° • Vacuum • Vibrations

…anti-matter (8) Particle identification in AMS The detectors need to be very precise. We need to be able to reject: 1 proton in 104 positons 1 Helium in 103 positons 1 électron in 102 positons 1 proton in 106 photons

Lets quickly go through history

Experiments that changed everything E. Rutherford, H. Geiger et E. Marsden sent Helium particles (alpha particles) on gold leaf/sheet. … Surprise: the gold leaf/sheet looks like butter containing very small particles. Rutherford will interpret these as Gold atom’s nuclei

Experiments that changed everything The mystery of beta disintegration ne 0 0 ne W. Pauli suggests a new particle: the neutrino

Experiments that changed everything 1 neutrino out 1020 interacts with the detector ! Reactor: 1020 neutrinos/s Detector at 12 m 3 neutrinos detected every hour The first neutrino detector. Built in 1956 by C. Cowan et F. Reines, near Savannah River’s nuclear reactor, USA water+cadmium

Experiments that changed everything 1968 SLAC: discovery of quarks Electrons-protons collisions 1974 SLAC and Brookhaven: discovery of quark « charme » electrons-positrons collisions 1977 Fermilab: discovery of quark « bottom » protons-protons collisions 1983 CERN: discovery of bosons W and Z protons-antiprotons collisions CERN: only three family of particles 1993 electrons-positrons collisions 1995 Fermilab: discovery of quark « top » proton-antiproton collisions

Today’s experiments Giant detectors for tiny particles… Super. Kamiokande track the sun’s neutrinos ALEPH detector studied high energy collisions

The theory that changed everything… quantum mechanics Some of the players E. Fermi W. Pauli L. De Broglie P. Dirac described weak interaction predicted the existence of the neutrino predicted wave-particle duality predicted the existence of anti-matter

Quantum mechanics a new way to see the invisible Particle and wave function: y Ey = Hy Distribution of the probability of finding an electron in an atom Orbitale 2 s Orbitale 2 p Orbitale 3 d z http: //hypo. ge. ch/physic/simulations/orbitales. html « Old » way to look at electrons in an atom

The mystery of quantum mechanics Thomas Young’s experiment with photons

The mystery of quantum mechanics Thomas Young’s experiment with electrons

Small particles… awsome consequences Thermonuclear bomb

Small particles… great consequences Proton therapy

Seeking to understand what matter is made out of… Trying to see the invisible… …has led to a better understanding of the human body, our Sun inner workings, the development of new materials (semiconductors) or new light sources (such as lasers)