- 2.3: Earliest Stages
- In 1927, the year in which the new quantum theory was introduced. In that year β decay was discovered as well: Some elements emit electrons with a continuous spectrum of energy. Energy conservation doesn’t allow for this possibility (nuclear levels are discrete!). This led to the realisation, in 1929, by Wolfgang Pauli that one needs an additional particle to carry away the remaining energy and momentum. This was called a neutrino,
- 2.12: Extraterrestrial Particle Physics
- One of the problems is that it is difficult to see how e can actually build a microscope that can look a a small enough scale, i.e., how we can build an accelerator that will be able to accelerate particles to high enough energies? The answer is simple – and has been more or less the same through the years: Look at the cosmos. Processes on an astrophysical scale can have amazing energies.
Thumbnail: A diagram summarizing the tree-level interactions between elementary particles described in the Standard Model. Vertices (darkened circles) represent types of particles, and edges (blue arcs) connecting them represent interactions that can take place. The organization of the diagram is as follows: the top row of vertices (leptons and quarks) are the matter particles; the second row of vertices (photon, W/Z, gluons) are the force mediating particles; and the bottom row is the Higgs boson. Image used with permission (Public Domain; TriTertButoxy).