The MSSM on amaretti

17Jun08

I’m finally back in the United States after being in the UK since 2006. I have plenty to write about returning to the US, but let me catch up with a few posts about my last days in the UK.

Regular readers know my fascination of putting physics on food (gingerbread, pancakes, pies), so below are some photos of the Minimal Supersymmetric Standard Model (MSSM) on amaretti.

Standard Model fermions and their superpartners:

Standard Model bosons and their superpartners: (note, it seems I’ve forgotten the charged Higgs! My apologies.)

Today’s physics lesson: this sector might not look like what you’d expect if you thought supersymmetry just doubles each of the Standard Model particles. First of all, anomaly cancellation and holomorphy of the superpotential (nevermind what these phrases mean) require there to be two Higgses. Each of these have a SUSY partner, the Higgsinos ($H_{u,d}$). Upon electroweak symmetry breaking, the eight real degrees of freedom of the two Higgs scalars decompose into Goldstone bosons for the Z and W, a light neutral Higgs ($h^0$), a heavy neutral Higgs ($H^0$), a CP-odd neutral Higgs ($A$), and a charged Higgs ($H^\pm$). The superpartners of the photon, Z, and W gauge bosons mix to produce the neutralinos ($\chi^0$) and charginos ($\chi^\pm$).

Finally, here’s a box diagram contributing to $B_s \rightarrow \bar\mu \mu$, featuring a McVittie’s digestive as a B-meson: