Chapter 29 Lecture. Particle Physics. Prepared by Dedra Demaree, Georgetown University Pearson Education, Inc.

Size: px
Start display at page:

Download "Chapter 29 Lecture. Particle Physics. Prepared by Dedra Demaree, Georgetown University Pearson Education, Inc."

Transcription

1 Chapter 29 Lecture Particle Physics Prepared by Dedra Demaree, Georgetown University

2 Particle Physics What is antimatter? What are the fundamental particles and interactions in nature? What was the Big Bang, and how has the universe evolved since?

3 Be sure you know how to: Use the right-hand rule to determine the direction of the magnetic force exerted by a magnetic field on a moving charged particle (Section 17.4). Explain beta decay (Section 28.6). Write an expression for the rest energy of a particle (Section 25.8).

4 What's new in this chapter Beta decay can produce antineutrinos, a form of antimatter. Every known particle has a corresponding antiparticle. In this chapter we investigate elementary particles such as the positron and their fundamental interactions. This area of physics is called particle physics.

5 Antiparticles By 1930, physicists had identified four particles: the electron, the proton, the neutron, and the photon. At that time, these were the only known truly elementary particles a description used to indicate the simplest and most basic particles. This view changed with the proposal and discovery of so-called antiparticles.

6 Antielectrons predicted Dirac predicted that free electrons would have an infinite number of possible quantum states with negative total energy. A free electron in a positive energy state should be able to transition to one of these negative energy states. How could a free electron have negative total energy? These negative energy states are occupied by an infinite number of positrons (then called antielectrons), a new type of particle that had not yet been observed.

7 Antielectrons detected

8 Pair production Under the right conditions, a photon can produce an electron and a positron:

9 Pair annihilation If an electron and a positron meet, it is possible for them to annihilate and produce a photon.

10 Conceptual Exercise 29.1 Imagine that an electron and a positron meet and annihilate each other. Assume that they are moving directly toward each other at constant speed. A. Will one or two photons be produced? Write a reaction equation for this process. B. In which directions do these photons move relative to each other after the process?

11 Beta-plus decay: Transforming a proton into a neutron If a proton captures a gamma-ray photon, the energy of the excited-state proton may be great enough to produce a neutron and the other particles. The proton absorbs the photon and then decays into a neutron, a positron, and a neutrino. This process is called beta-plus decay to indicate that a positron (not an electron) is produced.

12 Positron emission tomography Positron emission tomography (PET) is a process for imaging the brain. Fluorine-18 isotopes undergo beta-plus decay continually, producing positrons. The positrons meet electrons and annihilate each other, producing a pair of gamma-ray photons that move in opposite directions.

13 Other antiparticles The positively charged proton that is part of all nuclei has a negatively charged antiproton of the same mass but opposite electric charge. Even though the neutron has zero electric charge, it also has an antimatter counterpart; other properties besides charge differentiate the neutron from the antineutron. Occasionally, a particle is its own antiparticle; the photon is an example.

14 Fundamental interactions Fundamental interactions are the most basic interactions known, such as the electromagnetic interaction between charged particles. Nonfundamental interactions, such as friction, can be understood in terms of fundamental interactions. Friction is a macroscopic manifestation of the electromagnetic interaction between the electrons of two surfaces that are in contact.

15 Fundamental interactions: Gravitational interaction All objects in the universe participate in gravitational interactions due to their mass. This interaction is important for very massive (mega-) objects. It is much less important for objects in our daily lives and extremely insignificant for microscopic objects.

16 Fundamental interactions: Electromagnetic interaction Electrically charged objects participate in electromagnetic interactions. The interaction is electric if the objects are at rest or in motion with respect to each other. The interaction is magnetic only if the objects are moving with respect to each other. The electromagnetic interactions between nuclei and electrons are important in understanding the structure of atoms.

17 Comparing the electromagnetic interaction to the gravitational interaction The electrostatic force that an electron and a proton exert on each other in an atom is about times greater than the gravitational force that they exert on each other.

18 Fundamental interactions: Strong interaction The binding of protons and neutrons together into a nucleus is a residual interaction of the strong interaction. The strong interaction is a very short-range interaction, exerted by protons and neutrons only on their nearest neighbors within the nucleus.

19 Fundamental interactions: Weak interaction The weak interaction is responsible for beta decay. Protons, neutrons, electrons, and neutrinos all participate in it. The weak interaction is significantly weaker than the strong interaction and has a significantly shorter range.

20 Mechanisms of fundamental interactions This particle exchange mechanism has been successful in describing the weak and strong interactions. It has also had some success in describing the gravitational interaction. The emitted and absorbed particle is called a mediator. For the electromagnetic interaction, the mediator is the photon.

21 Interaction mediators Photons: electromagnetic interaction Gluons: strong interaction W and Z bosons: weak interaction Gravitons: gravitational interaction The mediators of the electromagnetic, strong, and weak interactions have all been discovered. The hypothetical mediator for the gravitational interaction, the so-called graviton, has not.

22 Fundamental interactions

23 Quantitative Exercise 29.2 Convert the masses of the W ± and Z 0 particles into electron volts.

24 Elementary particles and the Standard Model Particle accelerators facilitate collisions between particles with total energy significantly greater than the rest energies, allowing for additional particles to be produced. The properties of these additional particles can be determined using elaborate detectors. Most of the particles produced are not stable.

25 Leptons Leptons interact only through weak, electromagnetic, and gravitational interactions, but not through strong interactions. The electron and the electron neutrino are examples of leptons. These two particles form a generation (or family) of leptons.

26 Lepton generations (families)

27 Hadrons Two different types of hadrons can be distinguished: baryons and mesons. The proton and the neutron are baryons. In 1935, Hideki Yukawa suggested the existence of new particles that mediated the strong interaction the first example of a meson. In 1947, physicists discovered a meson in cosmic rays that participated in strong interactions and had the correct properties to be Yukawa's meson.

28 Properties of hadrons

29 Particle

30 Quarks Hadrons are made up of smaller, more fundamental particles that have fractional electric charge, known as quarks. Six different quarks have been discovered experimentally. These different quark types are known in the physics community as flavors.

31 Quarks

32 The proton and quark charge The total electric charge adds to e, and the total color is neutral.

33 Conceptual Exercise 29.3 Which combination of quarks will combine to have the correct properties to be a neutron?

34 Conceptual Exercise 29.3

35 Particles (matter) and their interactions

36 Confinement No experiment has ever produced a quark in isolation. Every quark and antiquark ever produced have always been part of a hadron. This phenomenon, called confinement, is an indication of a feature of the strong interaction. The strong interaction between quarks is weakest when they are close together and gets stronger the farther apart the quarks are.

37 Development of the Standard Model The Standard Model is the combined theory of the building blocks of matter and their interactions. In the late 1940s, physicists Feynman, Schwinger, and Tomonaga independently combined the ideas of special relativity and quantum mechanics into a single model that explains all electromagnetic phenomena. Their model, known as quantum electrodynamics (QED), is a cornerstone of the Standard Model.

38 Standard Model

39 Higgs particle In 1967, Glashow, Salam, and Weinberg independently put forth a model that unified the electromagnetic and weak interactions into a single interaction, which they called the electroweak model. This model predicted the existence of a particle, which became known as the Higgs particle after physicist Peter Higgs.

40 Predictions of the electroweak model In the very distant past when the universe was much smaller and very much hotter, all particles were massless. This situation led to the existence of the Higgs particle. As the universe cooled, the Higgs particle began interacting significantly with other elementary particles, reconfiguring them into the familiar forms they have today. This is known as the Higgs mechanism.

41 Quantum chromodynamics In 1973, using Yang's and Mills' mathematical framework, Fritzsch and Gell-Mann formulated quantum chromodynamics (QCD), a mathematical model of the strong interaction that plays a role in the exchange of gluons between quarks. Between 1976 and 1979, scientists discovered the tau lepton and bottom quark and found direct evidence for gluons.

42 Additional particle discovery timeline The 1980s brought the discoveries of the predicted weak interaction mediators W and Z. The 1990s gave us the top quark. In 2000, the tau neutrino was discovered. In July 2012, CERN announced the discovery of a particle that may be the long-sought-after Higgs particle.

43 Unanswered questions of the Standard Model 1. Can the strong interaction be unified with the electroweak interaction? 2. Why are there only three families of quarks/leptons? 3. Are the Standard Model particles truly fundamental? 4. Are there additional particles beyond those predicted by the Standard Model?

44 Summary of the Standard Model Quarks and leptons, which make up the matter of the universe The theory of strong interactions (QCD) mediated by gluons The theory of electromagnetic (QED) and weak interactions mediated by photons and the W and Z particles The Higgs particle, which explains, through the Higgs mechanism, why some of the fundamental particles have nonzero mass

45 Cosmology Why is our universe not filled with equal numbers of particles and antiparticles? Why is there an imbalance? These questions are answered in part by particle physics and by cosmology a branch of physics that studies the composition and evolution of the universe as a whole.

46 Big Bang

47 Standard Model

48 Inflation When the universe first became "cold" enough that quarks and leptons emerged as distinguishable particles, a fundamental change in the structure of the universe occurred, resulting in an extremely rapid exponential expansion known as cosmic inflation. During inflation, small fluctuations in the density of the universe decreased. Areas where the density was slightly above average would later act as the seeds of galaxy formation.

49 Nucleosynthesis A few minutes after the Big Bang, the temperature had dropped to about 1 billion K, and the average density of the universe was close to the density of air at sea level on Earth today. For the first time, protons and neutrons were able to combine to form the simplest nuclei: deuterium, helium, and trace amounts of lithium. This process is known as Big Bang nucleosynthesis.

50 Atoms, stars, and galaxies When the universe had cooled enough, gravitational interactions became the dominant driver of its further evolution. Density fluctuations led to the formation of the first galaxies and stars just 500,000 years after the Big Bang. These early stars went through their life cycles, with some ending in a violent collapse and explosion known as a supernova, which created heavier elements such as carbon, oxygen, iron, and gold.

51 Dark matter and dark energy When astronomers measure the mass of all the stars and gas that they can see, they find that the total mass is only about one-tenth of the mass needed to account for the speed of the solar system around the center of the galaxy. The universe is "missing" about 90% of the mass needed to account for the observed motion of stars and galaxies. How can this contradiction be resolved?

52 Dark matter In 1933, astrophysicist Fritz Zwicky speculated that there must be some unseen dark matter present in the Coma cluster; for about 40 years, his observation was the only evidence for its existence. In the 1970s, Vera Rubin presented further evidence. It was at this point that the dark matter explanation started to become more widely accepted.

53 Dark matter Dark matter does not emit photons or otherwise participate in the electromagnetic interaction (this is why it is called "dark"). Dark matter cannot be some sort of dark cloud of protons or gaseous atoms, because these could be detected by the scattering of radiation passing through them.

54 MACHOs: Massive compact halo objects These objects could be black holes, neutron stars, or brown dwarfs. Astronomers have detected MACHOs through their gravitational effects on the light from distant objects. The small number of detected events translates into MACHOs accounting for at most 20% of the dark matter in our galaxy. There must be another (or an additional) explanation.

55 WIMPs: Weakly interacting massive particles WIMPs are "weakly interacting": they can pass through ordinary matter with almost no interaction, and they neither absorb nor emit light. WIMPs are "massive": their mass is not zero. Prime candidates for WIMPs include neutrinos, axions, and neutralinos. Axions and neutralinos are not Standard Model particles and require the Standard Model to be extended to accommodate their existence.

56 Grand unified theories Grand unified theories combine the strong, weak, and electromagnetic interactions into a single interaction. These theories predict the existence of "sterile neutrinos," which could have even fewer interactions and be far more massive than Standard Model neutrinos. Physicists do not know how to detect such a particle. If it exists in sufficient abundance, it could account for dark matter.

57 Supersymmetry Supersymmetry is an extension of the Standard Model: It effectively doubles the number of elementary particles. It gives insight into the cosmological constant problem. It allows for a more precise understanding of the unification of interactions in grand unified theories. It gives a potential candidate for dark matter.

58 Explaining the accelerating expansion of the universe Invoke a discarded feature of Einstein's general theory of relativity (our current best model of the gravitational interaction) known as the cosmological constant. Suggest the existence of a strange kind of energy-fluid that fills space and has a repulsive gravitational effect. Propose a modified version of general relativity that includes a new kind of field that creates this cosmic acceleration.

59 The cosmological constant model The dominant model of the universe was the steady-state model, which asserted that the universe essentially did not change in any major way as time passed. General relativity predicted that a static universe was unstable. Einstein introduced the cosmological constant into general relativity in an attempt to allow the theory to accommodate a steady-state universe.

60 The dark energy model The cosmological constant seems to represent a type of dark energy that is present at every point in space with equal density. Even as the universe expands, the density does not decrease because it is a property of space itself. Dark energy has a negative pressure. In general relativity, this produces a gravitationally repulsive effect on space.

61 Modified general relativity Some better theory of the gravitational interaction would make even better predictions than general relativity. The challenge has been to construct the new theory in such a way that it does not make predictions that contradict experiments that have already been done. Thus far physicists have been unsuccessful in achieving this goal.

62 The proportion of matter, dark matter, and dark energy in the universe

63 Cosmological constant problem Dark energy is the sum of the zero-point energies of all quantum fields in the universe. When physicists predict values for the cosmological constant, they get a result that is times the observed value. This is the largest disagreement between prediction and experiment in all of science. This so-called cosmological constant problem is a major unsolved problem in physics.

64 Tip

65 Is our pursuit of knowledge worthwhile? Our models describe the behavior of only 4% of the content of our universe. The nature of the remaining 96% of our universe currently remains an unsolved problem. Will our eventual knowledge of the other 96% of the universe someday make people's lives better? It is impossible to say for sure, but history suggests that it very likely will.

66 Summary

67 Summary

Chapter 46. Particle Physics and Cosmology

Chapter 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 information

Chapter 22: Cosmology - Back to the Beginning of Time

Chapter 22: Cosmology - Back to the Beginning of Time Chapter 22: Cosmology - Back to the Beginning of Time Expansion of Universe implies dense, hot start: Big Bang Future of universe depends on the total amount of dark and normal matter Amount of matter

More information

An Introduction to Particle Physics

An Introduction to Particle Physics An Introduction to Particle Physics The Universe started with a Big Bang The Universe started with a Big Bang What is our Universe made of? Particle physics aims to understand Elementary (fundamental)

More information

1. What does this poster contain?

1. 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 information

FACULTY 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 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 information

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. 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 information

Lecture PowerPoint. Chapter 32 Physics: Principles with Applications, 6 th edition Giancoli

Lecture 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 information

John Ellison University of California, Riverside. Quarknet 2008 at UCR

John Ellison University of California, Riverside. Quarknet 2008 at UCR Overview of Particle Physics John Ellison University of California, Riverside Quarknet 2008 at UCR 1 Particle Physics What is it? Study of the elementary constituents of matter And the fundamental forces

More information

Particle Physics Outline the concepts of particle production and annihilation and apply the conservation laws to these processes.

Particle 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 information

Chapter 32 Lecture Notes

Chapter 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 information

2. The evolution and structure of the universe is governed by General Relativity (GR).

2. The evolution and structure of the universe is governed by General Relativity (GR). 7/11 Chapter 12 Cosmology Cosmology is the study of the origin, evolution, and structure of the universe. We start with two assumptions: 1. Cosmological Principle: On a large enough scale (large compared

More information

Lecture 36: The First Three Minutes Readings: Sections 29-1, 29-2, and 29-4 (29-3)

Lecture 36: The First Three Minutes Readings: Sections 29-1, 29-2, and 29-4 (29-3) Lecture 36: The First Three Minutes Readings: Sections 29-1, 29-2, and 29-4 (29-3) Key Ideas Physics of the Early Universe Informed by experimental & theoretical physics Later stages confirmed by observations

More information

Lecture 24: Cosmology: The First Three Minutes. Astronomy 111 Monday November 27, 2017

Lecture 24: Cosmology: The First Three Minutes. Astronomy 111 Monday November 27, 2017 Lecture 24: Cosmology: The First Three Minutes Astronomy 111 Monday November 27, 2017 Reminders Last star party of the semester tomorrow night! Online homework #11 due Monday at 3pm The first three minutes

More information

Fundamental Particles and Forces

Fundamental 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 information

Earlier in time, all the matter must have been squeezed more tightly together and a lot hotter AT R=0 have the Big Bang

Earlier in time, all the matter must have been squeezed more tightly together and a lot hotter AT R=0 have the Big Bang Re-cap from last lecture Discovery of the CMB- logic From Hubble s observations, we know the Universe is expanding This can be understood theoretically in terms of solutions of GR equations Earlier in

More information

Option 212: UNIT 2 Elementary Particles

Option 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 information

Phys 102 Lecture 28 Life, the universe, and everything

Phys 102 Lecture 28 Life, the universe, and everything Phys 102 Lecture 28 Life, the universe, and everything 1 Today we will... Learn about the building blocks of matter & fundamental forces Quarks and leptons Exchange particle ( gauge bosons ) Learn about

More information

Elementary Particle Physics Glossary. Course organiser: Dr Marcella Bona February 9, 2016

Elementary Particle Physics Glossary. Course organiser: Dr Marcella Bona February 9, 2016 Elementary Particle Physics Glossary Course organiser: Dr Marcella Bona February 9, 2016 1 Contents 1 Terms A-C 5 1.1 Accelerator.............................. 5 1.2 Annihilation..............................

More information

Astronomy 182: Origin and Evolution of the Universe

Astronomy 182: Origin and Evolution of the Universe Astronomy 182: Origin and Evolution of the Universe Prof. Josh Frieman Lecture 12 Nov. 18, 2015 Today Big Bang Nucleosynthesis and Neutrinos Particle Physics & the Early Universe Standard Model of Particle

More information

The Four Fundamental Forces. The Four Fundamental Forces. Gravitational Force. The Electrical Force. The Photon (γ) Unification. Mass.

The 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 information

Physics 4213/5213 Lecture 1

Physics 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 information

Chapter 30. Nuclear Energy and Elementary Particles

Chapter 30. Nuclear Energy and Elementary Particles Chapter 30 Nuclear Energy and Elementary Particles Processes of Nuclear Energy Fission A nucleus of large mass number splits into two smaller nuclei Fusion Two light nuclei fuse to form a heavier nucleus

More information

Most of Modern Physics today is concerned with the extremes of matter:

Most 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 information

Most of Modern Physics today is concerned with the extremes of matter:

Most 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 information

Bosons in the Zoo of Elementary Particles

Bosons in the Zoo of Elementary Particles Bosons in the Zoo of Elementary Particles Daniele Sasso * Abstract In this paper we want to raise the question concerning the physical identity of bosons and the function that they perform in the Non-Standard

More information

Chapter 22 Back to the Beginning of Time

Chapter 22 Back to the Beginning of Time Chapter 22 Back to the Beginning of Time Expansion of Universe implies dense, hot start: Big Bang Back to the Big Bang The early Universe was both dense and hot. Equivalent mass density of radiation (E=mc

More information

Moment of beginning of space-time about 13.7 billion years ago. The time at which all the material and energy in the expanding Universe was coincident

Moment of beginning of space-time about 13.7 billion years ago. The time at which all the material and energy in the expanding Universe was coincident Big Bang Moment of beginning of space-time about 13.7 billion years ago The time at which all the material and energy in the expanding Universe was coincident Only moment in the history of the Universe

More information

Chapter 22. Preview. Objectives Properties of the Nucleus Nuclear Stability Binding Energy Sample Problem. Section 1 The Nucleus

Chapter 22. Preview. Objectives Properties of the Nucleus Nuclear Stability Binding Energy Sample Problem. Section 1 The Nucleus Section 1 The Nucleus Preview Objectives Properties of the Nucleus Nuclear Stability Binding Energy Sample Problem Section 1 The Nucleus Objectives Identify the properties of the nucleus of an atom. Explain

More information

It is possible for a couple of elliptical galaxies to collide and become a spiral and for two spiral galaxies to collide and form an elliptical.

It is possible for a couple of elliptical galaxies to collide and become a spiral and for two spiral galaxies to collide and form an elliptical. 7/16 Ellipticals: 1. Very little gas and dust an no star formation. 2. Composed of old stars. 3. Masses range from hundreds of thousands to 10's of trillions of solar masses. 4. Sizes range from 3000 ly

More information

UNVEILING THE ULTIMATE LAWS OF NATURE: DARK MATTER, SUPERSYMMETRY, AND THE LHC. Gordon Kane, Michigan Center for Theoretical Physics Warsaw, June 2009

UNVEILING THE ULTIMATE LAWS OF NATURE: DARK MATTER, SUPERSYMMETRY, AND THE LHC. Gordon Kane, Michigan Center for Theoretical Physics Warsaw, June 2009 UNVEILING THE ULTIMATE LAWS OF NATURE: DARK MATTER, SUPERSYMMETRY, AND THE LHC Gordon Kane, Michigan Center for Theoretical Physics Warsaw, June 2009 OUTLINE! Some things we ve learned about the physical

More information

I V E R S U N. The Hot Big Bang I T Y T H E O F E. Andrew Liddle R G. Image: NASA/WMAP Science Team

I V E R S U N. The Hot Big Bang I T Y T H E O F E. Andrew Liddle R G. Image: NASA/WMAP Science Team The Hot Big Bang Andrew Liddle T H E O F E U N D I I V E R S N U B R G I T Y H Image: NASA/WMAP Science Team The Standard Model The discovery of the Higgs particle completes the Standard Model of Particle

More information

Project Paper May 13, A Selection of Dark Matter Candidates

Project Paper May 13, A Selection of Dark Matter Candidates A688R Holly Sheets Project Paper May 13, 2008 A Selection of Dark Matter Candidates Dark matter was first introduced as a solution to the unexpected shape of our galactic rotation curve; instead of showing

More information

The Standard Model of Particle Physics

The Standard Model of Particle Physics The Standard Model of Particle Physics Jesse Chvojka University of Rochester PARTICLE Program Let s s look at what it is Description of fundamental particles quarks and leptons Three out of Four (Forces)

More information

Lecture #25: Plan. Cosmology. The early Universe (cont d) The fate of our Universe The Great Unanswered Questions

Lecture #25: Plan. Cosmology. The early Universe (cont d) The fate of our Universe The Great Unanswered Questions Lecture #25: Plan Cosmology The early Universe (cont d) The fate of our Universe The Great Unanswered Questions Announcements Course evaluations: CourseEvalUM.umd.edu Review sheet #3 was emailed to you

More information

Hubble's Law. H o = 71 km/s / Mpc. The further a galaxy is away, the faster it s moving away from us. V = H 0 D. Modern Data.

Hubble's Law. H o = 71 km/s / Mpc. The further a galaxy is away, the faster it s moving away from us. V = H 0 D. Modern Data. Cosmology Cosmology is the study of the origin and evolution of the Universe, addressing the grandest issues: How "big" is the Universe? Does it have an "edge"? What is its large-scale structure? How did

More information

Chapter 27 The Early Universe Pearson Education, Inc.

Chapter 27 The Early Universe Pearson Education, Inc. Chapter 27 The Early Universe Units of Chapter 27 27.1 Back to the Big Bang 27.2 The Evolution of the Universe More on Fundamental Forces 27.3 The Formation of Nuclei and Atoms 27.4 The Inflationary Universe

More information

Introduction to the Standard Model of elementary particle physics

Introduction to the Standard Model of elementary particle physics Introduction to the Standard Model of elementary particle physics Anders Ryd (Anders.Ryd@cornell.edu) May 31, 2011 Abstract This short compendium will try to explain our current understanding of the microscopic

More information

Weak interactions and vector bosons

Weak 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 information

Electron-positron pairs can be produced from a photon of energy > twice the rest energy of the electron.

Electron-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 information

As a member of the Notre Dame community, I will not participate in, or tolerate, academic dishonesty.

As a member of the Notre Dame community, I will not participate in, or tolerate, academic dishonesty. Elementary Cosmology... Fall 2012 Final Exam... December 13, 2012... 10:30am-12:30pm Name: NetID: As a member of the Notre Dame community, I will not participate in, or tolerate, academic dishonesty. Please

More information

Big Bang Planck Era. This theory: cosmological model of the universe that is best supported by several aspects of scientific evidence and observation

Big Bang Planck Era. This theory: cosmological model of the universe that is best supported by several aspects of scientific evidence and observation Big Bang Planck Era Source: http://www.crystalinks.com/bigbang.html Source: http://www.odec.ca/index.htm This theory: cosmological model of the universe that is best supported by several aspects of scientific

More information

Option 212: UNIT 2 Elementary Particles

Option 212: UNIT 2 Elementary Particles Department of Physics and Astronomy Option 212: UNIT 2 Elementary Particles SCHEDULE 26-Jan-15 13.pm LRB Intro lecture 28-Jan-15 12.pm LRB Problem solving (2-Feb-15 1.am E Problem Workshop) 4-Feb-15 12.pm

More information

What is matter and how is it formed?

What is matter and how is it formed? What is matter and how is it formed? Lesson 6: Subatomic Particles Subatomic particles refers to particles that are more "fundamental" than... Are these fundamental particles or are they made up of smaller,

More information

FXA Candidates should be able to :

FXA Candidates should be able to : 1 Candidates should be able to : MATTER AND ANTIMATTER Explain that since protons and neutrons contain charged constituents called quarks, they are therefore, not fundamental particles. Every particle

More information

Astro-2: History of the Universe. Lecture 12; May

Astro-2: History of the Universe. Lecture 12; May Astro-2: History of the Universe Lecture 12; May 23 2013 Previously on astro-2 The four fundamental interactions are? Strong, weak, electromagnetic and gravity. We think they are unified at high energies,

More information

Matter: it s what you have learned that makes up the world Protons, Neutrons and Electrons

Matter: it s what you have learned that makes up the world Protons, Neutrons and Electrons Name The Standard Model of Particle Physics Matter: it s what you have learned that makes up the world Protons, Neutrons and Electrons Just like there is good and evil, matter must have something like

More information

Wesley Smith, U. Wisconsin, January 21, Physics 301: Introduction - 1

Wesley Smith, U. Wisconsin, January 21, Physics 301: Introduction - 1 Wesley Smith, U. Wisconsin, January 21, 2014 Physics 301: Introduction - 1 Physics 301: Physics Today Prof. Wesley Smith, wsmith@hep.wisc.edu Undergraduate Physics Colloquium! Discussions of current research

More information

Democritus, a fifth century B.C. philosopher, is credited with being the first

Democritus, a fifth century B.C. philosopher, is credited with being the first This paper will give a general overview of the current thoughts on the building blocks of atoms through the scope of the Standard Model. There will be an abridged explanation of the interactions that these

More information

Inflationary Universe and. Quick survey about iclickers Review of Big Bang model of universe Review of Evidence for Big Bang Examining Inflation

Inflationary Universe and. Quick survey about iclickers Review of Big Bang model of universe Review of Evidence for Big Bang Examining Inflation Inflationary Universe and Quick survey about iclickers Review of Big Bang model of universe Review of Evidence for Big Bang Examining Inflation Survey questions 1. The iclickers used in class encouraged

More information

Survey questions. Inflationary Universe and. Survey Questions. Survey questions. Survey questions

Survey questions. Inflationary Universe and. Survey Questions. Survey questions. Survey questions Inflationary Universe and Quick survey about iclickers Review of Big Bang model of universe Review of Evidence for Big Bang Examining Inflation Survey questions 1. The iclickers used in class encouraged

More information

1 Introduction. 1.1 The Standard Model of particle physics The fundamental particles

1 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 information

Finish up our overview of small and large

Finish up our overview of small and large Finish up our overview of small and large Lecture 5 Limits of our knowledge Clicker practice quiz Some terminology... "Elementary particles" = objects that make up atoms (n,p,e) or are produced when atoms

More information

Lab Monday optional: review for Quiz 3. Lab Tuesday optional: review for Quiz 3.

Lab Monday optional: review for Quiz 3. Lab Tuesday optional: review for Quiz 3. Announcements SEIs! Quiz 3 Friday. Lab Monday optional: review for Quiz 3. Lab Tuesday optional: review for Quiz 3. Lecture today, Wednesday, next Monday. Final Labs Monday & Tuesday next week. Quiz 3

More information

Cosmology and particle physics

Cosmology 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 information

32 IONIZING RADIATION, NUCLEAR ENERGY, AND ELEMENTARY PARTICLES

32 IONIZING RADIATION, NUCLEAR ENERGY, AND ELEMENTARY PARTICLES 32 IONIZING RADIATION, NUCLEAR ENERGY, AND ELEMENTARY PARTICLES 32.1 Biological Effects of Ionizing Radiation γ-rays (high-energy photons) can penetrate almost anything, but do comparatively little damage.

More information

The Big Bang Theory, General Timeline. The Planck Era. (Big Bang To 10^-35 Seconds) Inflationary Model Added. (10^-35 to 10^-33 Of A Second)

The Big Bang Theory, General Timeline. The Planck Era. (Big Bang To 10^-35 Seconds) Inflationary Model Added. (10^-35 to 10^-33 Of A Second) The Big Bang Theory, General Timeline The Planck Era. (Big Bang To 10^-35 Seconds) The time from the exact moment of the Big Bang until 10^-35 of a second later is referred to as the Planck Era. While

More information

General and Inorganic Chemistry I.

General and Inorganic Chemistry I. General and Inorganic Chemistry I. Lecture 2 István Szalai Eötvös University István Szalai (Eötvös University) Lecture 2 1 / 44 Outline 1 Introduction 2 Standard Model 3 Nucleus 4 Electron István Szalai

More information

THE STANDARD MODEL OF MATTER

THE STANDARD MODEL OF MATTER VISUAL PHYSICS ONLINE THE STANDARD MODEL OF MATTER The "Standard Model" of subatomic and sub nuclear physics is an intricate, complex and often subtle thing and a complete study of it is beyond the scope

More information

Astronomy 100 Exploring the Universe Tuesday, Wednesday, Thursday. Tom Burbine

Astronomy 100 Exploring the Universe Tuesday, Wednesday, Thursday. Tom Burbine Astronomy 100 Exploring the Universe Tuesday, Wednesday, Thursday Tom Burbine tomburbine@astro.umass.edu Mass-to-Light Ratio You can compare the measured mass to the luminosity of a galaxy Milky Way Milky

More information

Dark Energy or Repulsive Gravity

Dark Energy or Repulsive Gravity Dark Energy or Repulsive Gravity The leading theory to explain the accelerating expansion is the existence of a hypothetical repulsive force called dark energy. But in the new study, Massimo Villata, an

More information

FUNDAMENTAL PARTICLES CLASSIFICATION! BOSONS! QUARKS! FERMIONS! Gauge Bosons! Fermions! Strange and Charm! Top and Bottom! Up and Down!

FUNDAMENTAL 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 information

Tuesday, Thursday 2:30-3:45 pm. Astronomy 100. Tom Burbine

Tuesday, Thursday 2:30-3:45 pm.   Astronomy 100. Tom Burbine Astronomy 100 Tuesday, Thursday 2:30-3:45 pm Tom Burbine tburbine@mtholyoke.edu www.xanga.com/astronomy100 Schedule Today (end and beginning of the universe) May 3 (Does Life Exist Elsewhere in the Universe)

More information

Lecture Outlines Chapter 32. Physics, 3 rd Edition James S. Walker

Lecture Outlines Chapter 32. Physics, 3 rd Edition James S. Walker Lecture Outlines Chapter 32 Physics, 3 rd Edition James S. Walker 2007 Pearson Prentice Hall This work is protected by United States copyright laws and is provided solely for the use of instructors in

More information

Particle 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 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 information

Chapter 22 Lecture. The Cosmic Perspective. Seventh Edition. The Birth of the Universe Pearson Education, Inc.

Chapter 22 Lecture. The Cosmic Perspective. Seventh Edition. The Birth of the Universe Pearson Education, Inc. Chapter 22 Lecture The Cosmic Perspective Seventh Edition The Birth of the Universe The Birth of the Universe 22.1 The Big Bang Theory Our goals for learning: What were conditions like in the early universe?

More information

Unit 8.1 Nuclear Chemistry - Nuclear Reactions. Review. Radioactivity. State College Area School District Teacher: Van Der Sluys

Unit 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 information

Particle + Physics at ATLAS and the Large Hadron Coillder

Particle + Physics at ATLAS and the Large Hadron Coillder Particle + Physics at ATLAS and the Large Hadron Coillder Discovering the elementary particles of the Universe Kate Shaw The International Centre for Theoretical Physics + Overview Introduction to Particle

More information

The 64th Compton Lecture Series Unsolved Mysteries of the Universe: Looking for Clues in Surprising Places

The 64th Compton Lecture Series Unsolved Mysteries of the Universe: Looking for Clues in Surprising Places The 64th Compton Lecture Series Unsolved Mysteries of the Universe: Looking for Clues in Surprising Places Brian Odom Fall 2006 http://kicp.uchicago.edu/~odom/compton.htm Lecture 2: From the Big Bang to

More information

Review Chap. 18: Particle Physics

Review Chap. 18: Particle Physics Final Exam: Sat. Dec. 18, 2:45-4:45 pm, 1300 Sterling Exam is cumulative, covering all material Review Chap. 18: Particle Physics Particles and fields: a new picture Quarks and leptons: the particle zoo

More information

Particle Physics. All science is either physics or stamp collecting and this from a 1908 Nobel laureate in Chemistry

Particle 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 information

At this time the quark model consisted of three particles, the properties of which are given in the table.

At this time the quark model consisted of three particles, the properties of which are given in the table. *1 In 1961 Murray Gell-Mann predicted the existence of a new particle called an omega (Ω) minus. It was subsequently discovered in 1964. At this time the quark model consisted of three particles, the properties

More information

COSMOLOGY and DARK MATTER

COSMOLOGY and DARK MATTER Physics 10 1 st Lecture September 28, 2004 COSMOLOGY and DARK MATTER Joel Primack Introduction Modern cosmology the study of the universe as a whole is undergoing a scientific revolution. New ground- and

More information

BIG BANG SUMMARY NOTES

BIG BANG SUMMARY NOTES BIG BANG SUMMARY NOTES BIG BANG THEORY Studies of red-shifts of distant galaxies show that the universe is expanding. This and other observations has led to the Big Bang Theory The Big Bang Theory claims

More information

Origin of the Universe - 2 ASTR 2120 Sarazin. What does it all mean?

Origin of the Universe - 2 ASTR 2120 Sarazin. What does it all mean? Origin of the Universe - 2 ASTR 2120 Sarazin What does it all mean? Fundamental Questions in Cosmology 1. Why did the Big Bang occur? 2. Why is the Universe old? 3. Why is the Universe made of matter?

More information

NUCLEAR AND PARTICLE PHYSICS (PH242) PARTICLE PHYSICS

NUCLEAR AND PARTICLE PHYSICS (PH242) PARTICLE PHYSICS NUCLEAR AND PARTICLE PHYSICS (PH242) PARTICLE PHYSICS History of Elementary Particles THE CLASSICAL ERA (1897-1932) Elementary particle physics was born in 1897 with J.J. Thomson s discovery of the ELECTRONS

More information

The God particle at last? Astronomy Ireland, Oct 8 th, 2012

The 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 information

1PRELUDE: THE MYSTERY OF

1PRELUDE: THE MYSTERY OF 1PRELUDE: THE MYSTERY OF THE MISSING ANTIMATTER In the beginning what was the beginning? Every culture asks this question. Traditionally each finds some answer, a creation myth, a cosmology. These stories

More information

L23/24, part 1: let s end up with the story of relativity

L23/24, part 1: let s end up with the story of relativity L23/24, part 1: let s end up with the story of relativity Special relativity showed that space and time are not absolute Instead they are inextricably linked in a fourdimensional combination called spacetime

More information

Particles. Constituents of the atom

Particles. Constituents of the atom Particles Constituents of the atom For Z X = mass number (protons + neutrons), Z = number of protons Isotopes are atoms with the same number of protons number but different number of neutrons. charge Specific

More information

Gravitational Repulsion of Matter and Antimatter

Gravitational Repulsion of Matter and Antimatter Gravitational Repulsion of Matter and Antimatter The changing acceleration of the electrons explains the created negative electric field of the magnetic induction, the electromagnetic inertia, the changing

More information

The first 400,000 years

The first 400,000 years The first 400,000 years All about the Big Bang Temperature Chronology of the Big Bang The Cosmic Microwave Background (CMB) The VERY early universe Our Evolving Universe 1 Temperature and the Big Bang

More information

Cosmic Background Radiation

Cosmic Background Radiation Cosmic Background Radiation The Big Bang generated photons, which scattered frequently in the very early Universe, which was opaque. Once recombination happened the photons are scattered one final time

More information

The Physics of Particles and Forces David Wilson

The 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 information

The Goals of Particle Physics

The Goals of Particle Physics The Goals of Particle Physics Richard (Ryszard) Stroynowski Department of Physics Southern Methodist University History of Elementary Particles Science as a field of study derives from the Western Civilization

More information

The story of the Universe

The story of the Universe The story of the Universe From the Bi Ban to today's Universe Quantum ravity era Grand unification era Electroweak era Protons and neutrons form Nuclei are formed Atoms and liht era Galaxy formation Today

More information

Rapid Inflation of the Early Universe. 27. Exploring the Early Universe. The Isotropy Problem. Possible Causes of Cosmic Inflation

Rapid Inflation of the Early Universe. 27. Exploring the Early Universe. The Isotropy Problem. Possible Causes of Cosmic Inflation 27. Exploring the Early Universe Rapid inflation of the early Universe Mass & energy formed during inflation Most matter & antimatter annihilated each other Neutrinos & helium are primordial fireball relics

More information

Cosmology and particle physics

Cosmology and particle physics Fedora GNU/Linux; LATEX 2ɛ; xfig Cosmology and particle physics Mark Alford Washington University Saint Louis, USA Outline I Particle physics: What the universe is made of. quarks, leptons, and the forces

More information

One of elements driving cosmological evolution is the presence of radiation (photons) Early universe

One of elements driving cosmological evolution is the presence of radiation (photons) Early universe The Frontier Matter and Antimatter One of elements driving cosmological evolution is the presence of radiation (photons) Early universe Matter and antimatter But we live in universe full of matter -- where

More information

Chapter 27: The Early Universe

Chapter 27: The Early Universe Chapter 27: The Early Universe The plan: 1. A brief survey of the entire history of the big bang universe. 2. A more detailed discussion of each phase, or epoch, from the Planck era through particle production,

More information

Dark matter: summary

Dark matter: summary Dark matter: summary Gravity and detecting Dark Matter Massive objects, even if they emit no light, exert gravitational forces on other massive objects. m 1 r 12 m 2 We study the motions (dynamics) of

More information

Lecture 2: The First Second origin of neutrons and protons

Lecture 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 information

Plasma Universe. The origin of CMB

Plasma Universe. The origin of CMB Plasma Universe As we go back in time, temperature goes up. T=2.73(1+z) K At z~1100, T~3000 K About the same temperature as M-dwarfs Ionization of hydrogen atoms H + photon! p + e - Inverse process: recombination

More information

Atomic emission & absorption spectra

Atomic emission & absorption spectra Name: Date: Modern Physics Models of the Atom The word atom comes from the Greek word atomos meaning indivisible We now know that this model of the atom is not accurate JJ Thompson Experiment and atomic

More information

Nuclear 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 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 information

The physics of elementary particles

The physics of elementary particles 1997 2009, Millennium Mathematics Project, University of Cambridge. Permission is granted to print and copy this page on paper for non commercial use. For other uses, including electronic redistribution,

More information

ASTR 101 General Astronomy: Stars & Galaxies

ASTR 101 General Astronomy: Stars & Galaxies ASTR 101 General Astronomy: Stars & Galaxies ANNOUNCEMENTS FINAL EXAM: THURSDAY, May 14 th, 11:15am Last Astronomy public talk, May 8 th (up to 3% Extra class credit (see Blackboard announcement for details)

More information

i>clicker Quiz #14 Which of the following statements is TRUE?

i>clicker Quiz #14 Which of the following statements is TRUE? i>clicker Quiz #14 Which of the following statements is TRUE? A. Hubble s discovery that most distant galaxies are receding from us tells us that we are at the center of the Universe B. The Universe started

More information

The God particle at last? Science Week, Nov 15 th, 2012

The 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 information

DEVIL PHYSICS THE BADDEST CLASS ON CAMPUS IB PHYSICS

DEVIL 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 information

Introduction. Read: Ch 1 of M&S

Introduction. 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 information