Testing QED by measuring a He* tune-out wavelength

Abstract

We report a new measurement for the 413 nm tune-out wavelength for metastable helium (He*); the optical wavelength at which the light does not interact with the atom, whose accurate determination provides a sensitive test of QED independent of transition energy measurements. Mitroy and Tang have shown[1] that the 413nm tune-out wavelength of the metastable 23S1 state of helium is particularly sensitive to QED effects, and a measurement of this tune-out to 175MHz accuracy would constitute the most precise measurement of transition rate information made in Helium. Show more