Precision spectroscopy of high rotational states in H<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mrow/><mml:mn>2</mml:mn></mml:msub></mml:math>investigated by Doppler-free two-photon laser spectroscopy in the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>E</mml:mi><mml:mi>F</mml:mi></mml:mrow></mml:math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow/><mml:mn>1</mml:mn></mml:msup><mml:msubsup><mml:mi>Σ</mml:mi><mml:mi>g</mml:mi><mml:mo>+</mml:mo></mml:msubsup></mml:mrow></mml:math>–<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>X</mml:mi></mml:math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow/><mml:mn>1</mml:mn></mml:msup><mml:msubsup><mml:mi>Σ</mml:mi><mml:mi>g</mml:mi><mml:mo>+</mml:mo></mml:msubsup></mml:mrow></mml:math>system
Bibliographic record
Abstract
Recently a high precision spectroscopic investigation of the $EF{\phantom{\rule{0.16em}{0ex}}}^{1}{\ensuremath{\Sigma}}_{g}^{+}$--$X{\phantom{\rule{0.16em}{0ex}}}^{1}{\ensuremath{\Sigma}}_{g}^{+}$ system of molecular hydrogen was reported yielding information on QED and relativistic effects in a sequence of rotational quantum states in the $X{\phantom{\rule{0.16em}{0ex}}}^{1}{\ensuremath{\Sigma}}_{g}^{+}$ ground state of the H${}_{2}$ molecule [Salumbides et al., Phys. Rev. Lett. 107, 043005 (2011)]. The present paper presents a more detailed description of the methods and results. Furthermore, the paper serves as a stepping stone towards a continuation of the previous study by extending the known level structure of the $EF{\phantom{\rule{0.16em}{0ex}}}^{1}{\ensuremath{\Sigma}}_{g}^{+}$ state to highly excited rovibrational levels through Doppler-free two-photon spectroscopy. Based on combination differences between vibrational levels in the ground state, and between three rotational branches ($O$, $Q$, and $S$ branches) assignments of excited $EF{\phantom{\rule{0.16em}{0ex}}}^{1}{\ensuremath{\Sigma}}_{g}^{+}$ levels, involving high vibrational and rotational quantum numbers, can be unambiguously made. For the higher $E{F}^{\phantom{\rule{0.16em}{0ex}}1}{\ensuremath{\Sigma}}_{g}^{+}$ levels, where no combination differences are available, calculations were performed using the multichannel quantum defect method, for a broad class of vibrational and rotational levels up to $J=19$. These predictions were used for assigning high-$J$ $EF$ levels and are found to be accurate within 5 cm${}^{\ensuremath{-}1}$.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.012 | 0.002 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".