Thursday, September 18, 2025, 16:00
OFLG/402
Jean-Philippe Karr, LKB-Paris
Abstract:
The molecular hydrogen ions (H2+, HD+, and other isotopologues) are
among the most promising systems to push forward our knowledge of fundamental constants and spectroscopic
bounds on beyond-standard model interactions. Spectroscopy of HD+ already contributed to the
latest CODATA recommended value of the proton-electron mass ratio. I will review the methods and status
in both theory and experiment - with, for the latter, a focus on the ongoing H2+
two-photon spectroscopy project in our team. Then, the extraction of fundamental constants and new
physics bounds from available data will be discussed, as well as perspectives for future improvements.