New mesons! Let’s begin with a picture (from encarta) showing how new particles (states) were discovered back in the good old days:
Work on the big meson paper is continuing. I’m almost done with the isoscalar mesons. So in addition to describing just what these things are, I’m including a few lines on the new J/psi states, the X(3872), X(3940), X(3945), X(4260), and X(4360).
How to Find a New Hadron
Hadrons (mesons and baryons) are found by analyzing large numbers of particle interactions. When you plot the data, the graphs have little, uh, well the technical term is “bump” . Yes, hadrons, like children, begin as bumps. A hadron bump looks like this:
The above is from hep-ph/0510365. This bump happens to be one of the states, the X(3940), with which this post is concerned.