Next generation measurement of the electron electric dipole moment with heavy molecules.

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I'm doing research into the relationship between matter and antimatter. This relationship is one of the biggest mysteries in physics today. But before I get on to explaining why it's such a big mystery, I should explain a little about what antimatter is. All of the matter around us is made up of protons, neutrons and electrons. These subatomic particles combine together to make atoms, the elements, and then these atoms combine together to make everything we see around us, solid, liquid and gas. But this isn't the end of the subatomic story. As we've looked more carefully we've discovered that as well as protons, neutrons and electrons there are many more, much more elusive, subatomic particles. We've found these particles in odd places: in cosmic ray showers, some kinds of nuclear decays, and in the remnants of atoms that have been smashed in particle colliders. Physicists have tried to explain how these particles relate to one another, to bring order to the particle zoo. And they've been spectacularly succesful, coming up with a theory that is called the Standard Model. This Standard Model brings order to the hundreds of subatomic particles that we've discovered, sorting them into families with regular patterns, predicting their properties with incredible accuracy. It's one of the great triumphes of twentieth century physics. Now I can explain what antimatter is. One of the most striking features of the Standard Model is that it arranges the particles into pairs. Every particle has a partner with the opposite electrical charge called an anti-particle. These anti-particles are what we call antimatter. The Standard Model predicts that these anti-particles should obey all the same rules that normal particles do. Experiments have confirmed this, that particles and antiparticles behave in a very symmetric way. What goes for one goes for the other. This is the big mystery! If matter and antimatter obey just the same laws, if particles of matter and antimatter come in pairs, then where's all the antimatter? We would expect that there should be just as much of it as there is normal matter. But there's not. The whole world is made almost entirely of normal matter, with only tiny traces of antimatter. Astronomers have looked right to the edge of the visible universe and even then they see just matter, no great stashes of anitmatter. What happened to all the antimatter? It's this question that we are trying to answer. We hope to answer it by searching for tiny differences between the behaviour of matter and antimatter. Could these tiny differences be responsible for the near extinction of antimatter over the billions of years that the universe has been evolving? We've decided to study electrons. We can think of the electron as a little ball of electrical charge. What we do is measure whether this ball is round or not. Now, this might sound completely unrelated to the question of antimatter, but it's not. We have very strong evidence that tells us that unless electrons are _perfectly_ round, the matter and antimatter _can't_ behave in exactly the same way. So by making a very careful measurement of the electron's shape we can infer something about the nature of antimatter. All without having to make or use any actual antimatter - I think this is very elegant! So far we've checked the roundness of the electron to an incredible degree of precision: the equivalent would be measuring the diameter of the earth to better than the width of one human hair. And so far, we've seen no evidence of non-roundness. What we're planning on doing in the next few years is using some of the latest developments in atomic and molecular physics to make our experiment 1000 times more precise. With this increased precision we think we might be able to see a tiny deviation from perfect roundness and hopefully explain the mystery of the antimatter.