La classificazione delle particelle elementari The zoo of

La classificazione delle particelle elementari The zoo of the elementary particles Spezia Stefano Catania 21 Agosto 2013

Elementary particles Matter Quarks ? Force Carriers Leptons Quark-Lepton complementarity Hadrons Mesons Gravitons W & Z Bosons Photons Gluons Strong Baryons Nuclei Gravity Weak Electromagnetism Quantum Chromodynamics Electrodynamics Gravity Electroweak Theory Atoms Molecules Grand Unified Theory of everything

Raccomandazione (2006/962/CE) Tra le 8 competenze chiave per l’apprendimento permanente: q Comunicazione nelle lingue straniere q Competenza matematica e competenze di base in scienza e tecnologia q Competenza digitale

… con il CLIL? q q q q q 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 q Conoscenze ü Saper descrivere le principali famiglie di particelle elementari; ü Saper descrivere le principali interazioni e le loro fondamentali proprietà; q Abilità ed Attitudini essenziali (connessioni con la realtà) ü Essere in grado di leggere e capire un articolo divulgativo su particelle elementari e le loro interazioni.

LESSON PLAN: Lesson 1 q Introduction to … (tempo 10 minuti): MAIN QUESTION? q

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? q q In the ancient time: 4 elements 17 -19 th century – molecules and atoms molecules 20 th century – electrons, protons and neutrons Today – quarks and leptons The atom in the 20 th century. . . q Atoms reacts through chemical reactions q More than 100 atoms known (H, He, Fe …) q The internal structure is not well known

The Atomic modern Model atom q A cloud of electrons moving constantly around the nucleus q Protons and neutrons moving in the nucleus q Quarks moving in protons and neutrons

Sub-atomic dimensions Nucleus q The nucleus is small and dense. For a while it was thought to be point-like. q However, there were so many different nuclei as many atoms q Simplification: all nuclei are made of neutrons and protons!

Sub-atomic dimensions Nucleus are made of neutrons and protons! Neutrons and protons are made of quarks! Quarks and electrons are elementary particles!

Particle physics …small, smaller…extremely small!… small! > 30 soccer fields Point-like < 1 hair A small stone Point like

New particles q Collisions of electrons and nuclei in the cosmic rays and in the particle accelerators brought to the discovery of many other particles. q 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)

Cosa possiamo osservare con essa?

Cosa possiamo osservare con essa?

Teoria Lezione frontale (2. 5 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 Proton: u + d quark Neutron: u + d quark Carbon: 18 u, 18 d, 6 e- 2/3 Quarks -1/3 Leptons 0 -1

Pauli principle 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. Bosons Fermions Leptons and quarks Spin = 1/2 Baryons Spin = 1/2, 3/2, 5/2 … Spin = 1 Force carrier particles Spin = 0, 1, 2 …. Hadrons Mesons

Fermions: the fundamental components 1 st generation 2 nd generation Massa (Me. V) 3 rd generation Charge (e) 2/3 -1/3 0 0 -1 -1 Quarks Leptons

Matter and Anti-matter q For every particles there is a corresponding particle of antimatter, or anti-particle q These particles appear to be as their sisters of matter, but with opposite charge q Particles are created or destroyed with their antiparticles.

Forces in Nature There are 4 fundamental interactions! Gravity is very weak and is important at macroscopic distances In adding to the electrical charge, Quarks have another kind of charge called “color charge” The force carrier is the photon (γ) massless and move at the speed of light Weak interactions are responsible for the decays of heavy quarks and leptons The interactions are also responsible of the nucleus decays.

Forces in Nature Force Intensity Carriers 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 > 106 m (gravitational) R ~ 10 -11 - 10 -10 m (electroweak) R ~ 10 -15 m (strong nuclear)

The gluon A heavy nucleus contains many protons, all with positive charges. These protons repulse each others. Why the nucleus does not explode? The strong force keeps the quark together, to form the hadrons. The force carriers are the gluons: there are 8 different gluons.

Coloured quarks and gluons There are 3 colour charges and 3 anti-colour charges 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? q The SM cannot explain why a given particle is characterized by its mass. q Physicists “invented” a new particle, called Higgs boson, which interacts with all the other particles to give their masses. q Its discover has been announced on 4 July 2012 and confirmed in March 2013.

Fase applicativa (1, 5 ore): Utilizzo di Flash Learning Objects Applicazione guidata e controllata, con esercizi interattivi da parte degli studenti e supervisione costante dell'insegnante (approccio collaborativo). q Gruppi omogenei di alunni; q Gruppi eterogenei di alunni. THE FIREWORKS OF THE ELEMENTARY PARTICLE PHYSICS By Elena Symeonidou

Tra gli esercizi per casa… Applicazioni per dispositivi Android (giochi, simulatori, wallpaper, strumenti di misura virtuali, calcolatori, tascabili (pockets), …) Physics: The Standard Model

Verifica sommativa e valutazione q La verifica è fornita in inglese e propone quattro tipologie di esercizi: ü ü VERO O FALSO? RISPOSTA SINGOLA RISPOSTA MULTIPLA FRASI DA COMPLETARE q Gli esercizi possono essere risolti, senza che sia richiesto agli studenti la totale padronanza nella composizione in lingua inglese. Hanno invece sicuramente bisogno della comprensione durante la lettura per capire la consegna.

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! Single answer 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. a. b. c. d. What is the charge of a DOWN quark? -1; -1/3; 2/3; +1.

Esempio di prova di verifica Single answer 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.

Esempio di prova di verifica Single answer 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.

Esempio di prova di verifica True or False 1. Single quarks have been observed experimentally; False 2. 3 rd generation quarks (TOP and BOTTOM) are constituents of everyday matter; False 3. The W-, W+, and Z 0 bosons are carriers for the weak nuclear force which is responsible for radioactive decay; True 4. Me. V/c 2 and Ge. V/c 2 are units which are dimensionally equivalent to grams according to Einstein's equation, E = mc 2. False

Esempio di prova di verifica Multiple answer 1. Which of the fundamental force(s) have an infinite range? a. b. c. d. Electromagnetic; Gravitational; Strong Nuclear; Weak Nuclear.

Esempio di prova di verifica Complete the phrases Higgs boson gives particles their Interactions with the ______ unique masses; ______ and neutrinos are classified as leptons; Electrons Gluons are the bosons, or force carriers, for the _____ strong force which holds nuclear particles and the nucleus together;

Esempio di prova di verifica Open questions What is the difference between hadrons and leptons? What is the difference between fermions and bosons? What is the difference between baryons and mesons?

"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) The Particle Physicist’s Bible: Particle Data Book https: //pdg. lbl. gov Most particles are not stable and can decay to lighter particles. .

Bibliografia q Paul Davies, Superforza, Arnoldo Mondadori Editore S. p. A. 1986 q Ugo Amaldi, La fisica di Amaldi, Zanichelli editore, 2007 q George Gamow, The Great Physicists from Galileo to Einstein, Dover publications 1986 q Jonathan Allday, Quarks, Leptons and The Big Bang, IOP Publishing 2002 q M. G. Veltman, Martinus Veltman, Facts and Mysteries in Elementary Particle Physics, World Scientific Publishing- Singapore, Ed. 2003