Abstract

The HD (deuterated hydrogen) molecule is the simplest heteronuclear diatomic molecule, which has gained a growing interest for a variety of reasons, in recent years. The HD molecule represents a celebrated example of breaking of inversion symmetry, which, in conjunction to the breakdown of the Born-Oppenheimer approximation, gives rise to a small electric dipole moment (~10^-5 D) and, consequently, a very weak infrared spectrum following the selection rules of electric-dipole transitions. Since the molecule contains only two electrons, it is possible to perform highly-accurate ab initio calculations of its energy levels and transition dipole moments, taking into account adiabatic e non-adiabatic corrections, the finite nuclear mass contribution, relativistic and QED corrections [1]. Therefore, the comparison between theory and experiments can provide a stringent test on the application of QED to chemically-bound systems [2]. Furthermore, precision measurements of lince-center frequencies can lead to the extrapolation of an upper bound for the interaction strength of fifth forces between hadrons [3].

© 2015 IEEE