Theoretical progress in the H2+ molecular ion: towards electron to proton mass ratio determination

High resolution ro-vibrational spectroscopy of H-2(+) or HD+ can lead to a significantly improved determination of the electron to proton mass ratio m(e)/m(p) if the theoretical determination of transition frequencies becomes sufficiently accurate. We report on recent theoretical progress in the description of the hyperfine structure of H-2+, as well as first steps in the evaluation of radiative corrections at order m alpha(7). Completion of the latter calculation should allow us to reach the projected 10(-10) accuracy level and open the road to mass ratio determination.