I’m traveling, so you will have to rely on some of the many other physics bloggers talking about this year’s Nobel Prize in Physics: to Yoichiro Nambu, Makoto Kobayashi, and Toshihide Maskawa. Nambu was awarded for his work in spontaneous symmetry breaking, while Kobayashi and Maskawa for their work on flavor mixing between quarks. We’ve spoken about spontaneous symmetry breaking before; maybe someday we’ll blog about flavor mixing? The basic idea is that, when a quark decays via the weak interactions, it doesn’t just turn into a single other quark, but a mixture of three different quark flavors. A top quark, for example, can emit a W boson and turns mostly into a bottom quark, but there are trace amounts of down quark and strange quark in there as well.
Sadly, this is going to be one of those prizes which causes controversy, as some worthy winners were left out — the Nobel charter places a strict limit of three Laureates per Prize. Nambu’s Prize could easily have been shared with Jeffrey Goldstone, another pioneer of spontaneous symmetry breaking. And the Prize for Kobayashi and Maskawa could easily have been shared with Nicola Cabibbo, who worked out the case of two quark generations before it was generalized to three generations by Kobayashi and Maskawa. (There are, to be sure, important differences in the case of three generations; but it’s not called the CKM matrix for nothing.)
“Sadly,” that is, because the three winners are richly deserving, and shouldn’t have their recognition sullied by bickering over who else should have won. It’s a downside of prizes in general; not everyone can win, not everyone who deserves to. But hopefully it gets some people on the street excited about the exciting world of broken symmetries.