Fundamental Forces. David Morrissey. Key Concepts, March 15, 2013
|
|
- Marion Anderson
- 5 years ago
- Views:
Transcription
1 Fundamental Forces David Morrissey Key Concepts, March 15, 2013
2 Not a fundamental force...
3 Also not a fundamental force...
4 What Do We Mean By Fundamental? Example: Electromagnetism (EM) electric forces magnetic forces Van der Waals forces radio waves rainbows... These different phenomena are all manifestations of EM. EM is said to be a fundamental force.
5 The Four Fundamental Forces * 1. Electromagnetism (EM) binds atoms, light, shocks 2. Strong holds nuclei together 3. Weak source of nuclear decays 4. Gravity why you re sitting here * Force = way for particles to interact
6 Four Fundamental Forces * 1. Electromagnetism (EM) binds atoms, light, shocks 2. Strong holds nuclei together 3. Weak source of nuclear decays 4. Gravity why you re sitting here The Cold Hard Truth: These forces might not actually be fundamental. There may be more (or less) than four. * Force = way for particles to interact
7 How Do We Measure Forces? 1. Pull two particles apart: how much energy V(r) does this take? Need really good tweezers Scatter particles: Stronger Force Weaker Force Stronger Force More Scattering
8 Forces and Scattering dσ d(cosθ) (p 1,p 2 ) = differential scattering cross-section = prob. for particles to scatter with angle θ A 2 A is the quantum mechanical amplitude. p 1, p 2 are the initial momenta of the particles. p 1 p 1 θ p 2 p 2
9 For non-relativistic scattering, A d 3 x e i q x V( x) Ṽ( q) where q = ( p p ) is the momentum transfer. Ṽ( q) is the Fourier Transform of the potential. Also: V( x) = d 3 q (2π) 3e i q x Ṽ( q). Scattering experiments teach us about forces!
10 Electromagnetism (Relativistic) Scattering experiments yield A Ṽ(p) = Q 1Q 2 e 2 p 2, where p = (E, p) is the transferred 4-momentum, (Q 1 e) and (Q 2 e) are the electric charges of the particles. Fourier transforming (in the non-relativistic limit) gives V( x) = Q 1Q 2 e 2 4π 1 r. Science works (...)!
11 In relativistic quantum mechanics, A = 1 p 2 m 2, p2 = E 2 p 2 is the amplitude for a particle of mass m to propagate with momentum p. Interpret the electromagnetic force as being mediated by a massless particle - the photon. e e γ e e The photon travels at the speed of light. In fact, the photon is a particle of light (or EM radiation).
12 Feynman Diagram electron scattering: e e γ e e Feynman Diagram Compton scattering: γ γ e e e
13 Electromagnetism has a U(1) em gauge symmetry. The Hamiltonian for EM is invariant under: ψ(x) e iqα ψ(x) (charged particle wavefnctn) φ(x) φ(x) 1 α (scalar EM potential) e t A(x) A(x) 1 α (vector EM potential) e for any function α(x). This symmetry COMPLETELY fixes how the photon couples to charged matter. all of electromagnetism follows from this simple gauge symmetry principle!
14 Aside: General Structure of Ṽ(p) We ll see that Ṽ(p) has the same general structure for all forces we will look at: Ṽ(p) = g 2 S 1 p 2 m 2 Here, g = dimensionless coupling strength of the force S = dependence on particle spins 1 p 2 m 2 = propagation of the force mediator I won t say much at all about S today.
15 The Strong Force Binds quarks into baryons and mesons, holds nuclei together. baryon = qqq bound state e.g. p = (uud), n = (udd) meson = q q bound state e.g. π 0 = (uū, d d), K + = (u s) A ZX nucleus = [Zp + (A-Z)n] bound state e.g. 4 2 He = 2p+2n, 16 8 O = 8p+8n Of the elementary particles we have discovered, only quarks and gluons feel the strong force.
16 Elementary Particles of the Standard Model: Fermions Bosons u c t γ d s b g ν e e ν µ ν µ τ τ W Z + 0 h
17 In stuffed toy form:
18 Scattering experiments tell us that: Ṽ(p) = g 2 s (p2 ) p 2, p 2 GeV 2, quark scattering gnnπ 2 p 2 m 2, p 2 GeV 2, nucleon scattering π Why do we think both come from the same basic force? Why don t we see quarks at low energies?
19 Start with quark scattering (p GeV): Ṽ(p) g2 s p 2 1/p 2 massless mediator the gluon. g s describes the strength of the strong force. It depends on p : g s 1 GeV At p 1GeV the coupling blows up! This confines quarks and gluons into baryons and mesons: V( x) 1 r +Λ2 r, Λ GeV fm 1. p
20 At lower energies, look at nucleon scattering (p GeV) Ṽ(p) = g2 NNπ p 2 m 2 π The force is mediated (mostly) by pions. g NNπ is the residue of the strong force after confinement. (Like van der Waals forces between neutral atoms.) N N π N N
21 Fourier transforming Ṽ(p) gives V( x) = g2 Nππ 4π 1 r e m πr Yukawa force with range r 1/m π 1fm. This is the typical separation between nucleons in nuclei! (Yukawa proposed the pion based on the range of the force.)
22 The strong force is based on a SU(3) c gauge symmetry. U(1) = 1 1 unitary matrices = phase transformations. SU(N) = N N unitary matrices with (determinant = 1). SU(3) c interchanges the 3 colour charges carried by quarks. strong force = quantum chromodynamics = QCD This symmetry COMPLETELY fixes the strong force! Gluons also carry colour charge. (Photons have no EM charge.)
23 The Weak Force Allows decays forbidden by the EM and strong forces: n p ν e e π ν µ µ b c ν e e µ ν µ ν e e (d u ν e e at the quark level) (dū ν µ µ at the quark level) These decays are very slow compared to EM or strong, but they are the only ones that mix flavours. The weak force is much more interesting above 100GeV.
24 At lower energies, p 100GeV, scattering gives Ṽ(p) constant G F g2 w m 2 W with g w 0.6, m W 80GeV. Fourier transforming gives V( x) G F δ (3) ( x) zero range point interaction
25 The party starts at higher energies, p 100GeV: Ṽ(p) g 2 w p 2 m 2 W, g 2 w p 2 m 2 Z with g w 0.65, m W 80.4GeV, m Z 91.2GeV. For p m W this reduces to what we had before. Looks like a force mediated by particles with masses m W, m Z. W, Z W ± and Z 0 spin 1 bosons were discovered in the 1980 s.
26
27 Electroweak Unification A gauge symmetry principle joins the weak and EM forces into a single electroweak force. The symmetry group is SU(2) L U(1) Y, contains U(1) em. Most of this symmetry is hidden at low energies. Only the U(1) em subgroup of EM remains unhidden. Hiding the symmetry means: W ± and Z 0 gauge bosons acquire masses the weak force has a finite range m 1 W the weak force is much weaker than EM for p m W
28 SU(2) L U(1) Y has coupling constants g and g. They are related to g w and e by g w = g, e = gg / g 2 +g 2. A spin 0 Higgs boson particle is thought to induce this electroweak symmetry breaking. We re trying really hard to find it, but no luck so far.
29 More Forces, and not so Fundamental The Higgs is also thought to generate fermion masses. If it does, there are also new Higgs forces. For scattering of two fermions with masses m 1 and m 2, Ṽ(p) = (m 1m 2 /v 2 ) p 2 m 2 h with m h 100GeV and v = 174GeV. This is a new Yukawa-type force: V( x) = (m 1m 2 /v 2 ) 4π 1 r e m hr. The coupling strength to a fermion of mass m is m/v.
30 Strong and Electroweak Couplings: g s > g > g. This is at p 100GeV. (g s 1, g 0.65, g 0.35) All three couplings depend on the scattering energy: g s decreases going to higher energies g, g increase going to higher energies Does the strong force get weaker than the weak force? Maybe depends on what new physics is around.
31 With no new physics (except maybe a little supersymmetry): g s g? g 1 GeV 10 GeV It looks like the couplings all meet at a point! Maybe the strong and EW forces have a common origin? 16 p SU(3) c SU(2) L U(1) Y SU(5), SO(10), E 6,... gauge unification into a single force with coupling g U? Symmetry breaking would split them into components.
32 Gravity Much weaker than the other three fundamental forces. almost always negligible in laboratory experiments Scattering of masses m 1 and m 2 gives (p M Pl ) Ṽ(p) m 1m 2 M 2 Pl 1 p 2, with M Pl GeV = 1/ 8πG N. This gives Yay! V( x) = G Nm 1 m 2 r
33 Interpret gravity as being mediated by a graviton. massless spin 2 particle The graviton coupling strength to matter is m/m Pl. Graviton couplings are fixed by a gauge symmetry. Symmetry Group = Local Coordinate Transformations x x (x) This reproduces General Relativity at the classical level. We don t know what gravity does at energies above M Pl, where quantum corrections become important.
34 Summary Fundamental Forces The 4FF are all based on gauge symmetries. But we think there are more forces out there. And the fundamental forces might not be fundamental. We hope to learn much more at the LHC!
35
Overview. The quest of Particle Physics research is to understand the fundamental particles of nature and their interactions.
Overview The quest of Particle Physics research is to understand the fundamental particles of nature and their interactions. Our understanding is about to take a giant leap.. the Large Hadron Collider
More information1 Introduction. 1.1 The Standard Model of particle physics The fundamental particles
1 Introduction The purpose of this chapter is to provide a brief introduction to the Standard Model of particle physics. In particular, it gives an overview of the fundamental particles and the relationship
More informationPhysics 4213/5213 Lecture 1
August 28, 2002 1 INTRODUCTION 1 Introduction Physics 4213/5213 Lecture 1 There are four known forces: gravity, electricity and magnetism (E&M), the weak force, and the strong force. Each is responsible
More informationFUNDAMENTAL PARTICLES CLASSIFICATION! BOSONS! QUARKS! FERMIONS! Gauge Bosons! Fermions! Strange and Charm! Top and Bottom! Up and Down!
FUNDAMENTAL PARTICLES CLASSIFICATION! BOSONS! --Bosons are generally associated with radiation and are sometimes! characterized as force carrier particles.! Quarks! Fermions! Leptons! (protons, neutrons)!
More informationFACULTY OF SCIENCE. High Energy Physics. WINTHROP PROFESSOR IAN MCARTHUR and ADJUNCT/PROFESSOR JACKIE DAVIDSON
FACULTY OF SCIENCE High Energy Physics WINTHROP PROFESSOR IAN MCARTHUR and ADJUNCT/PROFESSOR JACKIE DAVIDSON AIM: To explore nature on the smallest length scales we can achieve Current status (10-20 m)
More informationParticle Physics Lectures Outline
Subatomic Physics: Particle Physics Lectures Physics of the Large Hadron Collider (plus something about neutrino physics) 1 Particle Physics Lectures Outline 1 - Introduction The Standard Model of particle
More informationNuclear and Particle Physics 3: Particle Physics. Lecture 1: Introduction to Particle Physics February 5th 2007
Nuclear and Particle Physics 3: Particle Physics Lecture 1: Introduction to Particle Physics February 5th 2007 Particle Physics (PP) a.k.a. High-Energy Physics (HEP) 1 Dr Victoria Martin JCMB room 4405
More informationParticle Physics. All science is either physics or stamp collecting and this from a 1908 Nobel laureate in Chemistry
Particle Physics JJ Thompson discovered electrons in 1897 Rutherford discovered the atomic nucleus in 1911 and the proton in 1919 (idea of gold foil expt) All science is either physics or stamp collecting
More informationCosmology and particle physics
Cosmology and particle physics Lecture notes Timm Wrase Lecture 5 The thermal universe - part I In the last lecture we have shown that our very early universe was in a very hot and dense state. During
More informationThe Standard Model (part I)
The Standard Model (part I) Speaker Jens Kunstmann Student of Physics in 5 th year at Greifswald University, Germany Location Sommerakademie der Studienstiftung, Kreisau 2002 Topics Introduction The fundamental
More informationINTRODUCTION TO THE STANDARD MODEL OF PARTICLE PHYSICS
INTRODUCTION TO THE STANDARD MODEL OF PARTICLE PHYSICS Class Mechanics My office (for now): Dantziger B Room 121 My Phone: x85200 Office hours: Call ahead, or better yet, email... Even better than office
More informationParticle Physics Lecture 1 : Introduction Fall 2015 Seon-Hee Seo
Particle Physics Lecture 1 : Introduction Fall 2015 Seon-Hee Seo Particle Physics Fall 2015 1 Course Overview Lecture 1: Introduction, Decay Rates and Cross Sections Lecture 2: The Dirac Equation and Spin
More informationcgrahamphysics.com Particles that mediate force Book pg Exchange particles
Particles that mediate force Book pg 299-300 Exchange particles Review Baryon number B Total # of baryons must remain constant All baryons have the same number B = 1 (p, n, Λ, Σ, Ξ) All non baryons (leptons
More informationMost of Modern Physics today is concerned with the extremes of matter:
Most of Modern Physics today is concerned with the extremes of matter: Very low temperatures, very large numbers of particles, complex systems Æ Condensed Matter Physics Very high temperatures, very large
More informationA first trip to the world of particle physics
A first trip to the world of particle physics Itinerary Massimo Passera Padova - 13/03/2013 1 Massimo Passera Padova - 13/03/2013 2 The 4 fundamental interactions! Electromagnetic! Weak! Strong! Gravitational
More informationMost of Modern Physics today is concerned with the extremes of matter:
Most of Modern Physics today is concerned with the extremes of matter: Very low temperatures, very large numbers of particles, complex systems Æ Condensed Matter Physics Very high temperatures, very large
More informationPhoton Coupling with Matter, u R
1 / 16 Photon Coupling with Matter, u R Consider the up quark. We know that the u R has electric charge 2 3 e (where e is the proton charge), and that the photon A is a linear combination of the B and
More information9.2.E - Particle Physics. Year 12 Physics 9.8 Quanta to Quarks
+ 9.2.E - Particle Physics Year 12 Physics 9.8 Quanta to Quarks + Atomic Size n While an atom is tiny, the nucleus is ten thousand times smaller than the atom and the quarks and electrons are at least
More informationChapter 32 Lecture Notes
Chapter 32 Lecture Notes Physics 2424 - Strauss Formulas: mc 2 hc/2πd 1. INTRODUCTION What are the most fundamental particles and what are the most fundamental forces that make up the universe? For a brick
More informationOption 212: UNIT 2 Elementary Particles
Department of Physics and Astronomy Option 212: UNIT 2 Elementary Particles SCHEDULE 26-Jan-15 13.00pm LRB Intro lecture 28-Jan-15 12.00pm LRB Problem solving (2-Feb-15 10.00am E Problem Workshop) 4-Feb-15
More informationModern Physics: Standard Model of Particle Physics (Invited Lecture)
261352 Modern Physics: Standard Model of Particle Physics (Invited Lecture) Pichet Vanichchapongjaroen The Institute for Fundamental Study, Naresuan University 1 Informations Lecturer Pichet Vanichchapongjaroen
More informationWeak interactions and vector bosons
Weak interactions and vector bosons What do we know now about weak interactions? Theory of weak interactions Fermi's theory of weak interactions V-A theory Current - current theory, current algebra W and
More information1. Introduction. Particle and Nuclear Physics. Dr. Tina Potter. Dr. Tina Potter 1. Introduction 1
1. Introduction Particle and Nuclear Physics Dr. Tina Potter Dr. Tina Potter 1. Introduction 1 In this section... Course content Practical information Matter Forces Dr. Tina Potter 1. Introduction 2 Course
More informationFundamental Particles and Forces
Fundamental Particles and Forces A Look at the Standard Model and Interesting Theories André Gras PHYS 3305 SMU 1 Overview Introduction to Fundamental Particles and Forces Brief History of Discovery The
More informationParticles in the Early Universe
Particles in the Early Universe David Morrissey Saturday Morning Physics, October 16, 2010 Using Little Stuff to Explain Big Stuff David Morrissey Saturday Morning Physics, October 16, 2010 Can we explain
More informationThe God particle at last? Astronomy Ireland, Oct 8 th, 2012
The God particle at last? Astronomy Ireland, Oct 8 th, 2012 Cormac O Raifeartaigh Waterford Institute of Technology CERN July 4 th 2012 (ATLAS and CMS ) A new particle of mass 125 GeV I The Higgs boson
More informationIsospin. K.K. Gan L5: Isospin and Parity 1
Isospin Isospin is a continuous symmetry invented by Heisenberg: Explain the observation that the strong interaction does not distinguish between neutron and proton. Example: the mass difference between
More informationFundamental Interactions (Forces) of Nature
Chapter 14 Fundamental Interactions (Forces) of Nature Interaction Gauge Boson Gauge Boson Mass Interaction Range (Force carrier) Strong Gluon 0 short-range (a few fm) Weak W ±, Z M W = 80.4 GeV/c 2 short-range
More informationPH5211: High Energy Physics. Prafulla Kumar Behera Room: HSB-304B
PH5211: High Energy Physics Prafulla Kumar Behera E-mail:behera@iitm.ac.in Room: HSB-304B Information Class timing: Wed. 11am, Thur. 9am, Fri. 8am The course will be graded as follows: 1 st quiz (20 marks)
More informationParticle Physics. Tommy Ohlsson. Theoretical Particle Physics, Department of Physics, KTH Royal Institute of Technology, Stockholm, Sweden
Particle Physics Tommy Ohlsson Theoretical Particle Physics, Department of Physics, KTH Royal Institute of Technology, Stockholm, Sweden International Baccalaureate T. Ohlsson (KTH) Particle Physics 1/
More informationQuantum Field Theory 2 nd Edition
Quantum Field Theory 2 nd Edition FRANZ MANDL and GRAHAM SHAW School of Physics & Astromony, The University of Manchester, Manchester, UK WILEY A John Wiley and Sons, Ltd., Publication Contents Preface
More information4. The Standard Model
4. The Standard Model Particle and Nuclear Physics Dr. Tina Potter Dr. Tina Potter 4. The Standard Model 1 In this section... Standard Model particle content Klein-Gordon equation Antimatter Interaction
More informationParticle Physics Outline the concepts of particle production and annihilation and apply the conservation laws to these processes.
Particle Physics 12.3.1 Outline the concept of antiparticles and give examples 12.3.2 Outline the concepts of particle production and annihilation and apply the conservation laws to these processes. Every
More informationQuark model. Jan 30, 2006 Lecture 8 1
Quark model Jan 30, 2006 Lecture 8 1 Quark model of hadrons!!!! Developed long before QCD was recognized as the appropriate quantum field theory of the strong interactions Postulate that 1.! All baryons
More informationDEVIL PHYSICS THE BADDEST CLASS ON CAMPUS IB PHYSICS
DEVIL PHYSICS THE BADDEST CLASS ON CAMPUS IB PHYSICS LSN 7-3: THE STRUCTURE OF MATTER Questions From Reading Activity? Essential Idea: It is believed that all the matter around us is made up of fundamental
More informationContents. Preface to the First Edition Preface to the Second Edition
Contents Preface to the First Edition Preface to the Second Edition Notes xiii xv xvii 1 Basic Concepts 1 1.1 History 1 1.1.1 The Origins of Nuclear Physics 1 1.1.2 The Emergence of Particle Physics: the
More informationEssential Physics II. Lecture 14:
Essential Physics II E II Lecture 14: 18-01-16 Last lecture of EP2! Congratulations! This was a hard course. Be proud! Next week s exam Next Monday! All lecture slides on course website: http://astro3.sci.hokudai.ac.jp/~tasker/teaching/ep2
More informationThe God particle at last? Science Week, Nov 15 th, 2012
The God particle at last? Science Week, Nov 15 th, 2012 Cormac O Raifeartaigh Waterford Institute of Technology CERN July 4 th 2012 (ATLAS and CMS ) A new particle of mass 125 GeV Why is the Higgs particle
More informationThe Scale-Symmetric Theory as the Origin of the Standard Model
Copyright 2017 by Sylwester Kornowski All rights reserved The Scale-Symmetric Theory as the Origin of the Standard Model Sylwester Kornowski Abstract: Here we showed that the Scale-Symmetric Theory (SST)
More informationThe Physics of Particles and Forces David Wilson
The Physics of Particles and Forces David Wilson Particle Physics Masterclass 21st March 2018 Overview David Wilson (TCD) Particles & Forces 2/30 Overview of Hadron Spectrum Collaboration (HadSpec) scattering
More informationAstronomy, Astrophysics, and Cosmology
Astronomy, Astrophysics, and Cosmology Luis A. Anchordoqui Department of Physics and Astronomy Lehman College, City University of New York Lesson IX April 12, 2016 arxiv:0706.1988 L. A. Anchordoqui (CUNY)
More informationNUCLEAR FORCES. Historical perspective
NUCLEAR FORCES Figure 1: The atomic nucleus made up from protons (yellow) and neutrons (blue) and held together by nuclear forces. Nuclear forces (also known as nuclear interactions or strong forces) are
More informationThe Standard Model. 1 st 2 nd 3 rd Describes 3 of the 4 known fundamental forces. Separates particle into categories
The Standard Model 1 st 2 nd 3 rd Describes 3 of the 4 known fundamental forces. Separates particle into categories Bosons (force carriers) Photon, W, Z, gluon, Higgs Fermions (matter particles) 3 generations
More informationQuantum ChromoDynamics (Nobel Prize 2004) Chris McLauchlin
Quantum ChromoDynamics (Nobel Prize 2004) Chris McLauchlin Outline The Four Fundamental Forces The Strong Force History of the Strong Force What These People Did Experimental Support 1 Fundamental Forces
More informationGian Gopal Particle Attributes Quantum Numbers 1
Particle Attributes Quantum Numbers Intro Lecture Quantum numbers (Quantised Attributes subject to conservation laws and hence related to Symmetries) listed NOT explained. Now we cover Electric Charge
More informationParticle Physics. Dr Victoria Martin, Spring Semester 2012 Lecture 1: The Mysteries of Particle Physics, or Why should I take this course?
Particle Physics Dr Victoria Martin, Spring Semester 2012 Lecture 1: The Mysteries of Particle Physics, or Why should I take this course? Contents: Review of the Standard Model! What we know! What we don
More informationMass. Chris Quigg Fermi National Accelerator Laboratory
Mass Chris Quigg Fermi National Accelerator Laboratory YITP@40 Stony Brook 4 May 2007 I. Newton (1687) Mass: the quantity of matter arising from its density and bulk conjointly F = ma + Universal Gravitation
More informationPhysics 7730: Particle Physics
Physics 7730: Particle Physics! Instructor: Kevin Stenson (particle physics experimentalist)! Office: Duane F317 (Gamow tower)! Email: kevin.stenson@colorado.edu! Phone: 303-492-1106! Web page: http://www-hep.colorado.edu/~stenson/!
More informationIntroduction to Elementary Particles
David Criffiths Introduction to Elementary Particles Second, Revised Edition WILEY- VCH WILEY-VCH Verlag GmbH & Co. KGaA Preface to the First Edition IX Preface to the Second Edition XI Formulas and Constants
More informationSTANDARD MODEL and BEYOND: SUCCESSES and FAILURES of QFT. (Two lectures)
STANDARD MODEL and BEYOND: SUCCESSES and FAILURES of QFT (Two lectures) Lecture 1: Mass scales in particle physics - naturalness in QFT Lecture 2: Renormalisable or non-renormalisable effective electroweak
More informationElectroweak Physics. Krishna S. Kumar. University of Massachusetts, Amherst
Electroweak Physics Krishna S. Kumar University of Massachusetts, Amherst Acknowledgements: M. Grunewald, C. Horowitz, W. Marciano, C. Quigg, M. Ramsey-Musolf, www.particleadventure.org Electroweak Physics
More informationIX. Electroweak unification
IX. Electroweak unification The problem of divergence A theory of weak interactions only by means of W ± bosons leads to infinities e + e - γ W - W + e + W + ν e ν µ e - W - µ + µ Divergent integrals Figure
More informationBeyond Standard Models Higgsless Models. Zahra Sheikhbahaee
Beyond Standard Models Higgsless Models Zahra Sheikhbahaee Standard Model There are three basic forces in the Universe: 1. Electroweak force, including electromagnetic force, 2. Strong nuclear force, 3.
More informationAN OVERVIEW OF QUANTUM CHROMODYNAMICS UNIVERSITY OF WASHINGTON PHYS575 FARRAH TAN 12/10/2015
AN OVERVIEW OF QUANTUM CHROMODYNAMICS UNIVERSITY OF WASHINGTON PHYS575 FARRAH TAN 12/10/2015 1 AGENDA SOME DEFINITIONS (QCD, FUNDAMENTAL FORCES) SOME HISTORY (THEORY, SLAC) GAUGE THEORY FLAVORS AND COLORS
More informationPHY-105: Introduction to Particle and Nuclear Physics
M. Kruse, Spring 2011, Phy-105 PHY-105: Introduction to Particle and Nuclear Physics Up to 1900 indivisable atoms Early 20th century electrons, protons, neutrons Around 1945, other particles discovered.
More informationRemainder of Course. 4/22 Standard Model; Strong Interaction 4/24 Standard Model; Weak Interaction 4/27 Course review 5/01 Final Exam, 3:30 5:30 PM
Remainder of Course 4/22 Standard Model; Strong Interaction 4/24 Standard Model; Weak Interaction 4/27 Course review 5/01 Final Exam, 3:30 5:30 PM Practice Final on Course Web Page See HW #12 (not to be
More informationLecture PowerPoint. Chapter 32 Physics: Principles with Applications, 6 th edition Giancoli
Lecture PowerPoint Chapter 32 Physics: Principles with Applications, 6 th edition Giancoli 2005 Pearson Prentice Hall This work is protected by United States copyright laws and is provided solely for the
More informationElementary particles and typical scales in high energy physics
Elementary particles and typical scales in high energy physics George Jorjadze Free University of Tbilisi Zielona Gora - 23.01.2017 GJ Elementary particles and typical scales in HEP Lecture 1 1/18 Contents
More information11 Group Theory and Standard Model
Physics 129b Lecture 18 Caltech, 03/06/18 11 Group Theory and Standard Model 11.2 Gauge Symmetry Electromagnetic field Before we present the standard model, we need to explain what a gauge symmetry is.
More informationPG lectures- Particle Physics Introduction. C.Lazzeroni
PG lectures- Particle Physics Introduction C.Lazzeroni Outline - Properties and classification of particles and forces - leptons and hadrons - mesons and baryons - forces and bosons - Relativistic kinematics
More informationFYS 3510 Subatomic physics with applications in astrophysics. Nuclear and Particle Physics: An Introduction
FYS 3510 Subatomic physics with applications in astrophysics Nuclear and Particle Physics: An Introduction Nuclear and Particle Physics: An Introduction, 2nd Edition Professor Brian Martin ISBN: 978-0-470-74275-4
More informationLecture 3: Propagators
Lecture 3: Propagators 0 Introduction to current particle physics 1 The Yukawa potential and transition amplitudes 2 Scattering processes and phase space 3 Feynman diagrams and QED 4 The weak interaction
More information2007 Section A of examination problems on Nuclei and Particles
2007 Section A of examination problems on Nuclei and Particles 1 Section A 2 PHYS3002W1 A1. A fossil containing 1 gramme of carbon has a radioactivity of 0.03 disintegrations per second. A living organism
More informationPARTICLE PHYSICS Major Option
PATICE PHYSICS Major Option Michaelmas Term 00 ichard Batley Handout No 8 QED Maxwell s equations are invariant under the gauge transformation A A A χ where A ( φ, A) and χ χ ( t, x) is the 4-vector potential
More informationParticle Physics. experimental insight. Paula Eerola Division of High Energy Physics 2005 Spring Semester Based on lectures by O. Smirnova spring 2002
experimental insight e + e - W + W - µνqq Paula Eerola Division of High Energy Physics 2005 Spring Semester Based on lectures by O. Smirnova spring 2002 Lund University I. Basic concepts Particle physics
More informationElementary (?) Particles
Elementary (?) Particles Dan Styer; 12 December 2018 This document summarizes the so-called standard model of elementary particle physics. It cannot, in seven pages, even touch upon the copious experimental
More information6. QED. Particle and Nuclear Physics. Dr. Tina Potter. Dr. Tina Potter 6. QED 1
6. QED Particle and Nuclear Physics Dr. Tina Potter Dr. Tina Potter 6. QED 1 In this section... Gauge invariance Allowed vertices + examples Scattering Experimental tests Running of alpha Dr. Tina Potter
More informationUnit 8.1 Nuclear Chemistry - Nuclear Reactions. Review. Radioactivity. State College Area School District Teacher: Van Der Sluys
Unit 8. Nuclear Chemistry - Nuclear Reactions State College Area School District Teacher: Van Der Sluys Review Atoms consist of electrons, protons and neutrons Atoms of elements are distinguished by the
More informationElectron-positron pairs can be produced from a photon of energy > twice the rest energy of the electron.
Particle Physics Positron - discovered in 1932, same mass as electron, same charge but opposite sign, same spin but magnetic moment is parallel to angular momentum. Electron-positron pairs can be produced
More informationSubatomic Physics: Particle Physics Study Guide
Subatomic Physics: Particle Physics Study Guide This is a guide of what to revise for the exam. The other material we covered in the course may appear in uestions but it will always be provided if reuired.
More informationInteractions and Fields
Interactions and Fields Quantum Picture of Interactions Yukawa Theory Boson Propagator Feynman Diagrams Electromagnetic Interactions Renormalization and Gauge Invariance Strong Interactions Weak and Electroweak
More informationSaturday Morning Physics -- Texas A&M University. What is Matter and what holds it together? Dr. Rainer J. Fries. January 27, 2007
Saturday Morning Physics -- Texas A&M University Particles and Forces What is Matter and what holds it together? Dr. Rainer J. Fries January 27, 2007 Zooming in on the World around us Particles and Forces
More informationSaturday Morning Physics -- Texas A&M University Dr. Rainer J. Fries
Saturday Morning Physics -- Texas A&M University Particles and Forces What is Matter and what holds it together? Dr. Rainer J. Fries January 27, 2007 Zooming in on the World around us Particles and Forces
More informationQuantum Field Theory. and the Standard Model. !H Cambridge UNIVERSITY PRESS MATTHEW D. SCHWARTZ. Harvard University
Quantum Field Theory and the Standard Model MATTHEW D. Harvard University SCHWARTZ!H Cambridge UNIVERSITY PRESS t Contents v Preface page xv Part I Field theory 1 1 Microscopic theory of radiation 3 1.1
More informationDr Victoria Martin, Prof Steve Playfer Spring Semester 2013
Particle Physics Dr Victoria Martin, Prof Steve Playfer Spring Semester 2013 Lecture 12: Mesons and Baryons Mesons and baryons Strong isospin and strong hypercharge SU(3) flavour symmetry Heavy quark states
More informationDEEP INELASTIC SCATTERING
DEEP INELASTIC SCATTERING Electron scattering off nucleons (Fig 7.1): 1) Elastic scattering: E = E (θ) 2) Inelastic scattering: No 1-to-1 relationship between E and θ Inelastic scattering: nucleon gets
More informationChapter 46. Particle Physics and Cosmology
Chapter 46 Particle Physics and Cosmology Atoms as Elementary Particles Atoms From the Greek for indivisible Were once thought to be the elementary particles Atom constituents Proton, neutron, and electron
More information1. What does this poster contain?
This poster presents the elementary constituents of matter (the particles) and their interactions, the latter having other particles as intermediaries. These elementary particles are point-like and have
More informationThe Particle World. This talk: What is our Universe made of? Where does it come from? Why does it behave the way it does?
The Particle World What is our Universe made of? Where does it come from? Why does it behave the way it does? Particle physics tries to answer these questions. This talk: particles as we understand them
More informationDerivation of Electro Weak Unification and Final Form of Standard Model with QCD and Gluons 1 W W W 3
Derivation of Electro Weak Unification and Final Form of Standard Model with QCD and Gluons 1 W 1 + 2 W 2 + 3 W 3 Substitute B = cos W A + sin W Z 0 Sum over first generation particles. up down Left handed
More informationElementary Particles, Flavour Physics and all that...
Elementary Particles, Flavour Physics and all that... 1 Flavour Physics The term Flavour physics was coined in 1971 by Murray Gell-Mann and his student at the time, Harald Fritzsch, at a Baskin-Robbins
More informationThe Building Blocks of Nature
The Building Blocks of Nature PCES 15.1 Schematic picture of constituents of an atom, & rough length scales. The size quoted for the nucleus here (10-14 m) is too large- a single nucleon has size 10-15
More informationPHYS 420: Astrophysics & Cosmology
PHYS 420: Astrophysics & Cosmology Dr Richard H. Cyburt Assistant Professor of Physics My office: 402c in the Science Building My phone: (304) 384-6006 My email: rcyburt@concord.edu My webpage: www.concord.edu/rcyburt
More informationThe Strong Interaction and LHC phenomenology
The Strong Interaction and LHC phenomenology Juan Rojo STFC Rutherford Fellow University of Oxford Theoretical Physics Graduate School course Lecture 2: The QCD Lagrangian, Symmetries and Feynman Rules
More informationQuantum Numbers. Elementary Particles Properties. F. Di Lodovico c 1 EPP, SPA6306. Queen Mary University of London. Quantum Numbers. F.
Elementary Properties 1 1 School of Physics and Astrophysics Queen Mary University of London EPP, SPA6306 Outline Most stable sub-atomic particles are the proton, neutron (nucleons) and electron. Study
More informationLecture 02. The Standard Model of Particle Physics. Part I The Particles
Lecture 02 The Standard Model of Particle Physics Part I The Particles The Standard Model Describes 3 of the 4 known fundamental forces Separates particles into categories Bosons (force carriers) Photon,
More informationPhysicsAndMathsTutor.com
OR K π 0 + µ + v ( µ ) M. (a) (i) quark antiquark pair OR qq OR named quark antiquark pair 0 (iii) us (b) (i) Weak any of the following also score mark: weak interaction weak interaction force weak nuclear
More informationChapter 1. Introduction
Chapter 1 Introduction 1.1 Fundamental Forces Particle physics is concerned with the fundamental constituents of matter and the fundamental forces through which the fundamental constituents interact among
More informationElementary particles, forces and Feynman diagrams
Elementary particles, forces and Feynman diagrams Particles & Forces quarks Charged leptons (e,µ,τ) Neutral leptons (ν) Strong Y N N Electro Magnetic Y Y N Weak Y Y Y Quarks carry strong, weak & EM charge!!!!!
More informationLecture 2: The First Second origin of neutrons and protons
Lecture 2: The First Second origin of neutrons and protons Hot Big Bang Expanding and cooling Soup of free particles + anti-particles Symmetry breaking Soup of free quarks Quarks confined into neutrons
More informationKern- und Teilchenphysik II Lecture 1: QCD
Kern- und Teilchenphysik II Lecture 1: QCD (adapted from the Handout of Prof. Mark Thomson) Prof. Nico Serra Dr. Marcin Chrzaszcz Dr. Annapaola De Cosa (guest lecturer) www.physik.uzh.ch/de/lehre/phy213/fs2017.html
More informationThe Discovery of the Higgs boson Matthew Herndon, University of Wisconsin Madison Physics 301: Physics Today. M. Herndon, Phys
The Discovery of the Higgs boson Matthew Herndon, University of Wisconsin Madison Physics 301: Physics Today M. Herndon, Phys 301 2018 1 The Periodic Table: The early 20 th century understanding of the
More informationThe Four Fundamental Forces. The Four Fundamental Forces. Gravitational Force. The Electrical Force. The Photon (γ) Unification. Mass.
The Four Fundamental Forces What are the four fundamental forces? The Four Fundamental Forces What are the four fundamental forces? Weaker Stronger Gravitational, Electromagnetic, Strong and Weak Nuclear
More informationAn Introduction to the Standard Model of Particle Physics
An Introduction to the Standard Model of Particle Physics W. N. COTTINGHAM and D. A. GREENWOOD Ж CAMBRIDGE UNIVERSITY PRESS Contents Preface. page xiii Notation xv 1 The particle physicist's view of Nature
More informationParticles and Interactions. Prof. Marina Cobal Corso Particelle ed interazioni fondamentali 2013/2014
Particles and Interactions Prof. Marina Cobal Corso Particelle ed interazioni fondamentali 2013/2014 What is the world made of? In the ancient time: 4 elements 19 century atoms Beginning 20 th century
More information- ~200 times heavier than the e GeV µ travels on average. - does not interact strongly. - does emit bremsstrahlung in
Muons M. Swartz 1 Muons: everything you ve ever wanted to know The muon was first observed in cosmic ray tracks in a cloud chamber by Carl Anderson and Seth Neddermeyer in 1937. It was eventually shown
More informationBeyond the standard model? From last time. What does the SM say? Grand Unified Theories. Unifications: now and the future
From last time Quantum field theory is a relativistic quantum theory of fields and interactions. Fermions make up matter, and bosons mediate the forces by particle exchange. Lots of particles, lots of
More informationWeak interactions. Chapter 7
Chapter 7 Weak interactions As already discussed, weak interactions are responsible for many processes which involve the transformation of particles from one type to another. Weak interactions cause nuclear
More informationIntroduction. Read: Ch 1 of M&S
Introduction What questions does this field address? Want to know the basic law of nature. Can we unify all the forces with one equation or one theory? Read: Ch 1 of M&S K.K. Gan L1: Introduction 1 Particle
More informationBack to Gauge Symmetry. The Standard Model of Par0cle Physics
Back to Gauge Symmetry The Standard Model of Par0cle Physics Laws of physics are phase invariant. Probability: P = ψ ( r,t) 2 = ψ * ( r,t)ψ ( r,t) Unitary scalar transformation: U( r,t) = e iaf ( r,t)
More information