High-accuracy laser spectroscopy of H2+ and the proton-electron mass ratio

• 成果类型: Article
• 署名作者: Alighanbari, S.; Schenkel, M. R.; Korobov, V. I.; Schiller, S.
• 署名单位: Heinrich Heine University Dusseldorf; Joint Institute for Nuclear Research - Russia
• 刊物名称: Nature
• ISSN/ISSBN: 0028-1493
• DOI: 10.1038/s41586-025-09306-2
• 发表日期: 2025-08-07
• 关键词: molecular-hydrogen ion; pure quantum states; hyperfine-structure; prospects

摘要

The molecular hydrogen ions (MHI) are three-body systems suitable for advancing our knowledge in several domains: fundamental constants, tests of quantum physics, search for new interparticle forces, tests of the weak equivalence principle(1) and, once the anti-molecule (p) over bar(p) over bare(+) becomes available, new tests of charge-parity-time-reversal invariance and local position invariance(1-3). To achieve these goals, high-accuracy laser spectroscopy of several isotopologues, in particular H-2(+), is required(4). Here we present a Doppler-free laser spectroscopy of a H-2(+) rovibrational transition, achieving line resolutions as large as 2.2 x 10(13). We accurately determine the transition frequency with 8 x 10(-12) fractional uncertainty. We also determine the spin-rotation coupling coefficient with 0.1 kHz uncertainty and its value is consistent with the state-of-the-art theory prediction(5). The combination of our theoretical and experimental H-2(+) data allows us to deduce a new value for the proton-electron mass ratio mp/me. It is in agreement with the value obtained from mass spectrometry and has 2.3 times lower uncertainty. From combined MHI, H/D and muonic H/D data, we determine the baryon mass ratio m(d)/m(p) with 1.1 x 10(-10) absolute uncertainty. The value agrees with the directly measured mass ratio(6). Finally, we present a match between a theoretical prediction and an experimental result, with a fractional uncertainty of 8.1 x 10(-12). Both results indicate a notable confirmation of the predictive power of quantum theory and the absence of beyond-the-standard-model effects at these levels.