Precise test of quantum electrodynamics and determination of fundamental constants with HD+ ions

Abstract

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Phase-Sensitive Vector Terahertz Electrometry from Precision Spectroscopy of Molecular Ions

“…The REMPD detection scheme proposed here estimates that a single datapoint may be recorded in 30 s, and the two-photon rovibrational line of HD + , which is used as frequency reference, may be defined within ten minutes. These timescales are comparable with the timescales of the recording of the rotational lines [37]. It is assumed that the laser can be referenced to the HD + line with an uncertainty at a fraction of its linewidth within a ten-minute timescale.…”

“…Specifically for HMI, the sub-Doppler spectroscopy techniques, namely two-photon spectroscopy [34,35] and trapped ion cluster transverse excitation spectroscopy [36], may improve significantly the resolution and the accuracy. Recently, the fundamental rotational transition of the HD + ion was probed with a fractional full-width at half-maximum (FWHM) linewidth of 3 × 10 −12 and a fractional uncertainty of 1.3 × 10 −11 [37]. In addition, the two-photon spectroscopy was demonstrated on the (v, L) = (0, 3)→(9, 3) transition with a fractional uncertainty of 2.9 × 10 −12 [38].…”

Precise measurement of deuteron mass raises hopes of solving the nuclear-mass puzzle

“…These two particles are bound by an electron, which acts like a vibrating spring. The rotational and vibrational frequencies of HD + reflect the deuteron and proton masses, as well as fundamental laws of physics 7,8 . But the interpretation of these laws has been hampered by inconsistent mass measurements.…”

“…Studies of these ions attempt to verify whether quantum electrodynamics -a theory that has been extremely successful at explaining the behaviour of particles and atoms -is also valid for molecules. However, the precision of this theory's predictions of rotational and vibrational frequencies of molecular hydrogen ions is severely hampered by the observed mass discrepancies 7,8 . Likewise, the contradictory mass values could impair the outcome of an experiment to determine the neutrino mass by studying the nuclear decay of tritium 2 , a radioactive isotope of hydrogen (Fig.…”

“…Cancer spread, or metastasis, is an inefficient process 6,7 , and many cancer cells die in the bloodstream. A major contributory factor is oxidative stress in tumour cells.…”