Improved Laboratory Values of the H{sub 2} Lyman and Werner Lines for Constraining Time Variation of the Proton-to-Electron Mass Ratio
- Laser Centre, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands)
- Laboratoire Photophysique Moleculaire, Universite de Paris-Sud, Orsay (France)
- Laboratorio de Espectroscopia e Laser, Instituto de Fisica, Universidade Federal Fluminense, Campus da Boa Viagem, Nitro, RJ 24210-340 (Brazil)
Two distinct high-accuracy laboratory spectroscopic investigations of the H{sub 2} molecule are reported. Anchor lines in the EF{sup 1}{sigma}{sub g}{sup +}-X{sup 1}{sigma}{sub g}{sup +} system are calibrated by two-photon deep-UV Doppler-free spectroscopy, while independent Fourier-transform spectroscopic measurements are performed that yield accurate spacings in the B{sup 1}{sigma}{sub u}{sup +}-EF{sup 1}{sigma}{sub g}{sup +} and I{sup 1}{pi}{sub g}-C{sup 1}{pi}{sub u} systems. From combination differences accurate transition wavelengths for the B-X Lyman and the C-X Werner lines can be determined with accuracies better than {approx}5x10{sup -9}, representing a major improvement over existing values. This metrology provides a practically exact database to extract a possible variation of the proton-to-electron mass ratio based on H{sub 2} lines in high-redshift objects. Moreover, it forms a rationale for equipping a future class of telescopes, carrying 30-40 m dishes, with novel spectrometers of higher resolving powers.
- OSTI ID:
- 21179946
- Journal Information:
- Physical Review Letters, Vol. 101, Issue 22; Other Information: DOI: 10.1103/PhysRevLett.101.223001; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
- Country of Publication:
- United States
- Language:
- English
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