Feb
21
February Café Scientifique
Posted by: Cafe Scientifique Vancouver | February 21, 2012 | Leave a Comment
Dear Café Scientifiquers,
“Something’s the Matter with Anti-Matter: There’s not enough of it”
About 13.7 billion years ago, our Universe was born in a Big Bang. That early universe was a big steaming stew of radiation and exactly equal numbers of particles and antiparticles. But somehow, a symmetry was broken, and a lopsided-ness arose, leaving a very small excess of matter over antimatter. And by the time the universe was less than a second old, essentially all the antimatter had annihilated with matter in bursts of light/energy, leaving a small residual excess of matter – which is all the matter we see in our universe; this is the matter we’re all made of.
The 2008 Nobel Prize in Physics was given to three particle physicists whose theory can explain how this lopsided universe evolved as having unequal parts matter and anti-matter, as predicted in the simplest Big Bang models.
The Standard Model of Particle Physics has been a triumph of particle physics – many thousands of experiments have confirmed predictions of this simple and elegant model. But it has at least 2 severe shortcomings: while it has been shown to accommodate matter-antimatter asymmetry, it can only do so at a level orders of magnitude too small to explain the matter-antimatter asymmetry of our universe. The other shortcoming is that it predicts a Higgs Boson, which has not yet been observed.
We’ll discuss the experimental program which has observed and studied the decays of hundreds of millions of B mesons (“beautiful mesons”), testing the Standard Model of Particle Physics to great precision. An overview of the experiment and results will be presented.