Our Lopsided Universe The Matter with Antimatter Dr

Our Lopsided Universe: The Matter with Antimatter Dr. Stephen J. Sekula Laboratory for Nuclear Science at the Massachusetts Institute of Technology 1

This lecture is made possible by. . . You! 2

Chapter 1 Matter and Anti-Matter 3

Courtesy of Alan Chou (SLAC) Matter and Anti-Matter 4

Einstein's Famous Equation Albert Einstein taught us that: Energy and solid mass are equivalent Image © The Albert Einstein Archives, The Jewish National & University Library, The Hebrew University of Jerusalem, Israel. 5

Paul Dirac: “Father of Anti-Matter” Paraphrasing his 1933 Nobel Prize speech: The electron has a partner with opposite electric charge but the same mass (weight), and they cancel each other The existence of the out electron (matter) begets the existence of the positron (anti-matter) 6

From the Star Trek: The Next Generation Technical Manual 7

The “Trek” of Anti-Matter 8

Anti-Matter and Medicine Ever had a PET scan? You've benefited from anti-matter! 9

Locally Grown Anti-Matter That's not going to solve any energy issues. . . but it's more than enough to begin tackling questions about the origin and nature of the universe! 10 10

Photo courtesy of SLAC 40 -inch bubble chamber, 1971 11

Photo courtesy of SLAC 40 -inch bubble chamber, 1971 12

Dirac's Historical Perspective “If we accept the view of complete symmetry between positive and negative electric charge so far as concerns the fundamental laws of Nature, we must regard it rather as an accident that the Earth (and presumably the whole Solar System), contains a preponderance of negative electrons and positive protons. ” “It is quite possible that for some of the stars it is the other way about. . . In fact, there may be half the stars of each kind. ” Paul A. M. Dirac, Nobel Laureate Speech, 1933 13

Chapter 2 The Big Mystery 14

Looking Out, Looking Back The Big Dipper. . . Light travels at 186, 000 miles per second, or 6 trillion miles per year! Many of these stars are 80 light-years away –- that's 480, 000, 000 miles! 15 15

No Evidence of Anti-Matter. . . No evidence of equal parts anti-matter and matter for many billions of light-years in any direction. . . 16 16

? WHERE DID ALL THE ANTI-MATTER GO? ? ? The Mystery. . . 17

The Last Echo of the Big Bang Image taken by the Wilkinson Microwave Anisotropy Probe (WMAP) The Cosmic Microwave Background, a result of matter/anti-matter annihilation near the beginning of time. 18

Courtesy of Alan Chou (SLAC) 19 19

Chapter 3 Journey to the Beginning 20

The Cosmic Time Machine To try to solve this mystery, we have to go back to a time beyond the sight of our most powerful telescopes 5, 400°F -455°F Studying the universe at very high energy (high temperature) is equivalent to studying it when it was very young. . . (Now) 21

“Little Bangs” ● If the Big Bang created the universe, what we make at SLAC could be termed “little bangs” That's 1 billionth of a second after the Big Bang! ● We currently recreate conditions at a temperature of 120, 000, 000 degrees Fahrenheit 22

Snapshots of the Beginning. . . 23

Courtesy of Alan Chou (SLAC) 24

Layout courtesy of CERN Six “Bricks”: Leptons Discovery of the Tau Lepton, 1995 Nobel Prize: Dr. Martin Perl (SLAC) and Dr. Frederick Reines (UC Irvine) 25

Layout courtesy of CERN Six “Bricks”: Quarks Evidence for quarks: 1990 Nobel Prize to Dr. Jerome Friedman (MIT), Dr. Henry Kendall (MIT), and Dr. Richard Taylor (SLAC) Charm quark discovery: 1976 Nobel Prize to Dr. Burton Richter (SLAC) and Dr. Samuel Ting (MIT) 26

The Cement Gravity Electro-magnetism Carried by: photons Binds anything with electric charge Chemistry is a direct result Graphic courtesy of CERN Carried by: unknown Binds anything with mass Galaxies, orbits, weight. 27

More Cement Carried by gluons Results in the strength of the atomic nucleus The Weak Nuclear Force Carried by weak bosons Nuclear instability Merges with electro-magnetism to form a single force at high energy. Graphic courtesy of CERN The Strong Nuclear Force 28

Chapter 4 Lopsidedness 29

What is Ba. Bar? 30

. . . A Particle Detector. . . located at one of two “B Meson Factories” in the world (the other is KEK/Belle, in Tsukuba, Japan). . . 31

. . . A Collaboration. . . over 600 physicists from 75 institutions in 10 countries. . . 32

. . . Part of the SLAC “B-Factory” 33

What is a Meson? A Meson is a pair of quarks, bound by the Strong Force b d A 0 “B ” Meson 34

Looking for Lopsidedness B 0 Meson positron 50% Matter 50% Anti-Matter electron Is it still 50% matter and 50% anti-matter? ? ? anti-B 0 Meson 35

Lopsidedness Revealed! 36

Enough Lopsidedness? The Standard Model is the single most successful theory of nature ever developed. . . but it is not enough. . . 37

Great Challenges to Physics ● ● Matter/Anti-Matter asymmetry falls outside the Standard Our Universe Model Recent experiments show just how little we know and how much we don't know about our universe The domain of the Standard Model 38

The Quest Continues! ● ● ● Our lopsided universe is a result, not an accident. . . – It is testably lopsided! We can see it happen! – A result of what? What are we missing? To understand why, we have to connect the miniscule and the cosmic! Physicists at SLAC and across the globe are challenging these and many other questions head-on! 39

More SLAC Public Lectures! http: //www. slac. stanford. edu/lectures ● ● “Metals, Molecules, Life, and Death” – Graham George (August 31, 2004) – Metals are a boon and a bane to living organisms. Learn about their role in life, and how the Stanford Synchrotron Radiation Laboratory (SSRL) reveals the story! Particle Astrophysics – Roger Blandford (October 26, 2004) – Learn about the connections between the minute and the cosmic, and how SLAC is trying to shed light on the “missing” 95% of our universe! 40

Please join us for refreshments in the lobby! Physicists are here tonight to chat with you! 41