Direct Measurement of the Forbidden $2^3{S}_1\to 3^3{S}_1$ Atomic Transition in Helium

K. F. Thomas, J. A. Ross, B. M. Henson +4

We present the detection of the highly forbidden $2^3{S}_1\to 3^3{S}_1$ atomic transition in helium, the weakest transition observed in any neutral atom. Our measureme…