Blog 16: 2-Hour Meeting Answer #2

Essential Question: Why is finding supersymmetric particles an important task for physicists to undertake?

Answer 2: Supersymmetry is the one of the only theories that can completely solve the hierarchy problem of the Standard Model.

1. The hierarchy problem is one of the biggest inconsistencies of the Standard Model. We have observed the mass of the Higgs Boson to be ~125 GeV. The trouble is that the mass should be much greater than that due to a phenomenon called "quantum corrections." Without some very tight fine-tuning between the quantum corrections and the regular mass, this seems impossible. However, physicists don't like unexplained fine-tunings.

2. The Higgs Boson will couple to the most massive particles in the Standard Model, thus most of the quantum corrections to its mass will come from those particles, such as the top quark, which is the heaviest Standard Model particle. Supersymmetry predicts the existence of a stop squark partner for the top quark. As it turns out, the corrections from the stop squark should cancel with those from the top quark, leaving just enough left over to give us the Higgs mass we see in nature.
 (Contributions from both-assume one negative and one positive contribution, where UV is the Planck scale.)

3. There isn't a theory that explains the hierarchy problem so cleanly and accurately. If supersymmetry doesn't exist, it is important that physicists begin work on another theory so we do not have any unexplained fine-tunings. Therefore it is important that we continue the search for supersymmetric particles, just in case we have to start work on another theory.

Source: Warped Passages by Lisa Randall. I could never really wrap my head around the hierarchy problem but she made it very clear and understandable, and she explains why supersymmetry is such a good solution for it.

I plan to bulk up on my knowledge of Quantum Field Theory, and on Richard Feynman's work. I never cared for Feynman as a person, but as Einstein would say, "There is no emotion in science!*" I want to be able to create my own Feynman diagrams so I can better understand them.

*Einstein didn't really say this.