Presentation on theme: "La classificazione delle particelle elementari Spezia Stefano Catania 21 Agosto 2013 The zoo of the elementary particles."— Presentation transcript:
La classificazione delle particelle elementari Spezia Stefano Catania 21 Agosto 2013 The zoo of the elementary particles
Elementary particles Mesons Baryons Nuclei Atoms Molecules Quark-Lepton complementarity Matter Quarks Leptons Hadrons ? Theory of everything Force Carriers Gluons W & Z Bosons Gravitons Photons Strong Quantum Chromodynamics Gravity Quantum Gravity Weak Electromagnetism Quantum Electrodynamics Electroweak Theory Grand Unified Theory
Raccomandazione (2006/962/CE) le 8 competenze chiave per lapprendimento permanente: Tra le 8 competenze chiave per lapprendimento permanente: Comunicazione nelle lingue straniere Competenza matematica e competenze di base in scienza e tecnologia Competenza digitale
… con il CLIL? Titolo del modulo: The zoo of the elementary particles Classe: V Liceo Scientifico Raccordi interdisciplinari: Chimica, Inglese Competenze linguistiche: Inglese Risorse e strumenti: Lavagna Interattiva Multimediale (LIM) Periodo scolastico: ultime 3 settimane di Maggio Prerequisiti: Meccanica (Forze ed interazioni, Teoremi di conservazione); Meccanica relativistica (Equivalenza massa-energia, dilatazione del tempo); Elementi di Quanti, Materia e Radiazione. Numero di ore: 8,5 Compresenza: Insegnante di Inglese (3,5 ore)
Obiettivi: Competenze per i giovani Conoscenze Saper descrivere le principali famiglie di particelle elementari; Saper descrivere le principali interazioni e le loro fondamentali proprietà; Abilità ed Attitudini essenziali (connessioni con la realtà) Essere in grado di leggere e capire un articolo divulgativo su particelle elementari e le loro interazioni.
The world around us 1. What is the world made of? 2. What are the building blocks that could not be further divided? 3. What is the smallest particle you know? Look at the following links and find information about the building blocks of our world: http://www.infn.it/multimedia/particle/paitaliano/summary_sm.html http://www.infn.it/multimedia/particle/paitaliano/exp_start.html http://www.infn.it/multimedia/particle/paitaliano/beyond_start.html
What is the world made of? 4 elements In the ancient time: 4 elements moleculesatoms 17-19 th century – molecules and atoms electrons, protons neutrons 20 th century – electrons, protons and neutrons quarks and leptons Today – quarks and leptons The atom in the 20 th century... Atoms reacts through chemical reactions More than 100 atoms known (H, He, Fe …) The internal structure is not well known
Atomic Model The modern atom A cloud of electrons moving constantly around the nucleus Protons and neutrons moving in the nucleus Quarks moving in protons and neutrons
Sub-atomic dimensions Nucleus The nucleus is small and dense. For a while it was thought to be point-like. However, there were so many different nuclei as many atoms Simplification: all nuclei are made of neutrons and protons!
Sub-atomic dimensions Nucleus Nucleus are made of neutrons and protons! Neutrons protons Neutrons and protons are made of quarks! Quarks electrons Quarks and electrons are elementary particles!
Particle physics Point like Point-like …small, smaller…extremely small! …small, smaller…extremely small!… A small stone< 1 hair > 30 soccer fields
New particles Collisions of electrons and nuclei in the cosmic rays and in the particle accelerators brought to the discovery of many other particles. At the beginning it was thought that all these particles were fundamentals.
How can we observe these particles? 1897 - Joseph John Thomson discovers a particle, later called Electron
Laboratorio con materiale povero: camera a nebbia FAI DA TE (2 ore)
Standard model A theory has been developed that seems to explain quite well what we do observe in nature. This model includes 6 quarks, 6 leptons and 13 particles which carry the force in between quarks and leptons.
Example of the standard model Quarks Leptons 2/3 - 1/3 0 Proton: u + u + d quark Neutron: u + d + d quark Carbon: 18 u, 18 d, 6 e -
Pauli principle Fermions Leptons and quarks BaryonsBosons Force carrier particles Mesons Spin = 1/2 Spin = 1 Spin = 1/2, 3/2, 5/2 … Spin = 0, 1, 2 …. Bosons all fall into the lowest energy state, forming a Bose Einstein condensate. Fermions, must obey the Pauli exclusion principle, which prohibits two identical particles from occupying the same state. Hadrons
Fermions: the fundamental components Quarks Leptons 2/3 - 1/3 0 1 st generation2 nd generation 3 rd generation 2/3 - 1/3 0 Massa (MeV) Charge (e)
Matter and Anti-matter For every particles there is a corresponding particle of anti-matter, or anti-particle These particles appear to be as their sisters of matter, but with opposite charge Particles are created or destroyed with their antiparticles.
The interactions are also responsible of the nucleus decays. Forces in Nature There are 4 fundamental interactions! Gravity is very weak and is important at macroscopic distances The force carrier is the photon (γ) - massless and move at the speed of light In adding to the electrical charge, Quarks have another kind of charge called color charge Weak interactions are responsible for the decays of heavy quarks and leptons
Forces in Nature ForceIntensityCarriers Happens in Strong Nuclear~ 1 Gluons (massless) Atomic nuclea Elettromagnetic~ 10 -3 Photons (massless) Atomic levels Weak Nuclear~10 -5 W +,W -,Z 0 (heavy) Beta radioactive decay Gravitation~10 -38 Gravitons (not observed) Heavy bodies Interactions happen by exchange of one or more particles (carriers or bosons)
Forces and distances R ~ 10 -15 m (strong nuclear) R ~ 10 -11 - 10 -10 m (electroweak) R > 10 6 m (gravitational)
A heavy nucleus contains many protons, all with positive charges. These protons repulse each others. Why the nucleus does not explode? The gluon The strong force keeps the quark together, to form the hadrons. The force carriers are the gluons: there are 8 different gluons.
There are 3 colour charges and 3 anti-colour charges Coloured quarks and gluons Every quark has one of the three colour charges and every anti-quark has one of the three anti-colour charges Baryons R + G + B = white Mesons color + anti-color = white
Baryons and Mesons as coloured quarks All baryons, such as the proton and neutron shown here, are composed of three quarks. All mesons, such as the pions shown here, are composed of a quark-antiquark pair.
What can we say about mass? The SM cannot explain why a given particle is characterized by its mass. Physicists invented a new particle, called Higgs boson, which interacts with all the other particles to give their masses. Its discover has been announced on 4 July 2012 and confirmed in March 2013.
Fase applicativa (1,5 ore): Utilizzo di Flash Learning Objects THE FIREWORKS OF THE ELEMENTARY PARTICLE PHYSICS By Elena Symeonidou Applicazione guidata e controllata, con esercizi interattivi da parte degli studenti e supervisione costante dell'insegnante (approccio collaborativo). Gruppi omogenei di alunni; Gruppi eterogenei di alunni.
Tra gli esercizi per casa… Applicazioni per dispositivi Android (giochi, simulatori, wallpaper, strumenti di misura virtuali, calcolatori, tascabili (pockets),…) Physics: The Standard Model
Esempio di prova di verifica (1.5 ore) Try to make each initial answer correct. Don't just guess - research and show me that you have learned the correct answers. Be careful! 1.What is the charge of an UP quark (in unit of the elementary charge e)? a.-1; b.-1/3; c.2/3; d.+1. 2.What is the charge of a DOWN quark? a.-1; b.-1/3; c.2/3; d.+1. Single answer
Esempio di prova di verifica 3.What is the quark composition of a proton? 3.ddd; 4.ddu; 5.duu; 6.uuu. 4.What is the quark composition of a neutron? a.ddd; b.ddu; c.duu; d.uuu. Single answer
Esempio di prova di verifica 5.Which of the four fundamental forces is not included in the Standard Model? a.Electromagnetic; b.Gravitational; c.Strong Nuclear; d.Weak Nuclear. 6.Which of the fundamental forces has a range of only a few angstroms (0.1 nm)? a.Electromagnetic; b.Gravitational; c.Strong Nuclear; d.Weak Nuclear. Single answer
1.Single quarks have been observed experimentally; 2.3 rd generation quarks (TOP and BOTTOM) are constituents of everyday matter; 3.The W -, W +, and Z 0 bosons are carriers for the weak nuclear force which is responsible for radioactive decay; 4.MeV/c 2 and GeV/c 2 are units which are dimensionally equivalent to grams according to Einstein's equation, E = mc 2. True or False Esempio di prova di verifica False True False
1.Which of the fundamental force(s) have an infinite range? a.Electromagnetic; b.Gravitational; c.Strong Nuclear; d.Weak Nuclear. Esempio di prova di verifica Multiple answer
Interactions with the ______ boson gives particles their unique masses; ______ and neutrinos are classified as leptons; Gluons are the bosons, or force carriers, for the _____ force which holds nuclear particles and the nucleus together; Esempio di prova di verifica Complete the phrases Higgs Electrons strong
What is the difference between hadrons and leptons? What is the difference between fermions and bosons? What is the difference between baryons and mesons? Esempio di prova di verifica Open questions
The Particle Physicists Bible: Particle Data Book https://pdg.lbl.gov "Young man, if I could remember the names of these particles, I would have been a botanist! E. Fermi to his student L. Lederman (both Nobel laureates) Most particles are not stable and can decay to lighter particles..
Bibliografia Paul Davies, Superforza, Arnoldo Mondadori Editore S. p. A. 1986 Ugo Amaldi, La fisica di Amaldi, Zanichelli editore, 2007 George Gamow, The Great Physicists from Galileo to Einstein, Dover publications 1986 Jonathan Allday, Quarks, Leptons and The Big Bang, IOP Publishing 2002 M. G. Veltman, Martinus Veltman, Facts and Mysteries in Elementary Particle Physics, World Scientific Publishing- Singapore, Ed. 2003