Who was the Dutch theoretical physicist that created the 't Hooft η symbol?
Gerard 't Hooft Gerardus (Gerard) 't Hooft (] ; born July 5, 1946) is a Dutch theoretical physicist and professor at Utrecht University, the Netherlands. He shared the 1999 Nobel Prize in Physics with his thesis advisor Martinus J. G. Veltman "for elucidating the quantum structure of electroweak interactions".
Bohr magneton In atomic physics, the Bohr magneton (symbol "μ") is a physical constant and the natural unit for expressing the magnetic moment of an electron caused by either its orbital or spin angular momentum.