Updates on this blog have been kind of sporadic over the past couple months, I know. Part of the reason for that is that the posts I want to do involve some research which I haven't entirely had time for, but besides that, I've also been busy preparing for my presentation at Quark Matter 2012! This is a physics conference that focuses on the study of the strong force in systems that contain lots of quarks and gluons — not just individual protons and neutrons, but entire atomic nuclei as well.
The particular piece of research I'll be presenting is about the particle reaction : a proton collides with an atomic nucleus (the ) and produces an electron-positron pair, a pion, and other junk which we don't care about (the ). The electron and positron themselves are produced from a (virtual) photon, so when you get down to the core of it, the reaction is really : a quark from the proton and a gluon from the nucleus interact to give a quark and a photon.
What we're interested in is the angle between that outgoing quark and the outgoing photon. Studying the distribution of that angle can yield some information about the quantum "structure" of gluons in protons, neutrons and nuclei. Specifically, what it helps us to understand is the dipole gluon distribution, a function which is necessary to create a complete model of the proton but is nevertheless rather difficult to actually measure. The research I'm presenting lays some of the groundwork for actually relating measurements to this function.
Despite the lack of blog posts, I have been reasonably active on Twitter, and I'll continue to do so throughout the conference. There aren't going to be any major announcements (nothing on the scale of the Higgs announcement, anyway) at Quark Matter, but I'll see if I can frame some of the results from proton structure research to make them understandable. And I'll be back probably after this coming week with more insights on the Higgs mechanism!