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

2 This lecture is made possible by You!

3 Chapter 1 Matter and Anti-Matter

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

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

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

7 From the Star Trek: The Next Generation Technical Manual

8 The “Trek” of Anti-Matter

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

10 Locally Grown Anti-Matter SLAC has produced a total of pounds of positrons over the last 20 years. Convert it all to energy over that time: 33 Watts of power 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! 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

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

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

13 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

14 Chapter 2 The Big Mystery

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

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

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

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

19 Courtesy of Alan Chou (SLAC)

20 Chapter 3 Journey to the Beginning

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

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

23 Snapshots of the Beginning...

24 Courtesy of Alan Chou (SLAC)

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

26 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) Layout courtesy of CERN

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

28 More Cement The Strong Nuclear Force 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

29 Chapter 4 Lopsidedness

30 What is BaBar?

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

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

33... Part of the SLAC “B-Factory” We produce “B” mesons and their anti-matter counter-parts, written “ B”. “B and B-bar = BaBar” 33

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

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

36 Lopsidedness Revealed!

37 Enough Lopsidedness? Galileo Galilei used the telescope as an instrument to understand the universe... The Standard Model Particle physicists use a mathematical tool called “The Standard Model” to do the same... The Standard Model is the single most successful theory of nature ever developed but it is not enough...

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

39 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!

40 More SLAC Public 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!

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