Spin Polarization

In proton NMR (for example) the proton spins are polarized in thermal equilibrium by application of a strong magnetic field which splits the energy of spin-up and spin-down protons by the Zeeman energy and thus favours the population of the spin-up state - but not by much!

By contrast, the muon's polarization is a consequence of the mass difference between the left-handed W boson and its hypothetical right-handed partner - a difference of at least 400 GeV!

It is amusing to compare the temperatures or magnetic fields that would be required to achieve a similar polarization of protons....

Jess H. Brewer
Last modified: Fri Nov 28 16:16:05 EST