Abstract

We have observed the 1S—3S and 1S—3D Doppler-free two-photon transitions in atomic hydrogen using a powerful narrow-band tunable light source at 205 nm. The excitation is monitored by looking at the fluorescent light emitted on the Balmer α transition. By this method we have been able to detect atomic hydrogen and atomic deuterium at low density (around 10⁷-10⁸ at/cm³). One of the possible applications of this method is the search of superheavy hydrogen atoms. These atoms composed of a heavy proton and an electron are predicted by some supersymmetry theories.1 Because of their important mass shift, they should be easily distinguishable from hydrogen, deuterium, or tritium. Using a preliminary centrifugation, we believe that we can improve the present limit (~10⁻¹⁵) on the abundance of these superheavy atoms.

© 1989 Optical Society of America