Speaker
Description
Spectroscopy of the HD$^+$ molecular ion has made a ''quantum'' leap in recent years, reaching part-per-trillion precision by use of techniques for Doppler-free excitation. The theoretical precision has also been improved, both in the spin-averaged transition frequencies and in hyperfine structure.
Under the assumption that the Standard Model correctly describes the physics of HD$^+$, comparison between theory and experiment can be used to improve the determination of the proton-electron mass ratio. I will briefly describe a recent reanalysis of experimental data in the perspective of the adjustment of fundamental constants.
Using independent values of the particle masses deduced from Penning trap measurements, one can exploit HD$^+$ spectroscopy to constrain hypothetical interactions beyond the standard model. Here, a global approach to combine different types of spectroscopic data is desirable, keeping in mind that the vlaues of fundamental constants themselves could be affected by the New Physics being tested. I will present a self-consistent solution to this problem, and results of a first implementation of this method.
