Precision spectroscopy of H2 and a possible variation of m p/me over cosmological time

W. Ubachs

doi:10.1063/1.2400631

Precision spectroscopy of H2 and a possible variation of m p/me over cosmological time

W. Ubachs^*

^*Corresponding author for this work

Quantum Metrology & Laser Applications

Research output: Chapter in Book / Report / Conference proceeding › Conference contribution › Academic › peer-review

Abstract

A novel and highly accurate (at the level of Δλ/λ = 5 × 10^-8) database of 233 spectral lines in the Lyman and Werner bands of H₂ is determined via laboratory spectroscopy employing a narrowband and tunable extreme ultraviolet laser system. Furthermore an updated set of so-called K_i coefficients, representing the sensitivity of each spectral line on a variation of the proton-to-electron mass ratio μ = m_p/m_e are derived for all lines in the H₂ spectrum. The laboratory wavelengths and K_i's are used in a comparison with a recent set of highly accurate H₂ spectral lines observed in the Q 0347-383 and Q 0405-443 quasars yielding a fractional change in the mass-ratio of Δμ/μ, = 2.4 ± 0.6 × 10 ^-5 (1σ). This result indicates, at a 4σ confidence level, that μ may have decreased in the past 12 billion years.

Original language	English
Title of host publication	AIP Conference Proceedings
Pages	37-43
Number of pages	7
Volume	869
Edition	1
DOIs	https://doi.org/10.1063/1.2400631
Publication status	Published - 2006
Event	20th International Conference on Atomic Physics, ICAP 2006 - Innsbruck, Austria Duration: 16 Jul 2006 → 21 Jul 2006

Conference

Conference	20th International Conference on Atomic Physics, ICAP 2006
Country/Territory	Austria
City	Innsbruck
Period	16/07/06 → 21/07/06

Keywords

Fundamental constants
Molecular hydrogen
Precision spectroscopy
Quasar absorption

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10.1063/1.2400631

https://research.vu.nl/admin/files/2731041/ICAP-UBACHS-H2.pdf

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title = "Precision spectroscopy of H2 and a possible variation of m p/me over cosmological time",

abstract = "A novel and highly accurate (at the level of Δλ/λ = 5 × 10-8) database of 233 spectral lines in the Lyman and Werner bands of H2 is determined via laboratory spectroscopy employing a narrowband and tunable extreme ultraviolet laser system. Furthermore an updated set of so-called Ki coefficients, representing the sensitivity of each spectral line on a variation of the proton-to-electron mass ratio μ = mp/me are derived for all lines in the H2 spectrum. The laboratory wavelengths and Ki's are used in a comparison with a recent set of highly accurate H2 spectral lines observed in the Q 0347-383 and Q 0405-443 quasars yielding a fractional change in the mass-ratio of Δμ/μ, = 2.4 ± 0.6 × 10 -5 (1σ). This result indicates, at a 4σ confidence level, that μ may have decreased in the past 12 billion years.",

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author = "W. Ubachs",

year = "2006",

doi = "10.1063/1.2400631",

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N2 - A novel and highly accurate (at the level of Δλ/λ = 5 × 10-8) database of 233 spectral lines in the Lyman and Werner bands of H2 is determined via laboratory spectroscopy employing a narrowband and tunable extreme ultraviolet laser system. Furthermore an updated set of so-called Ki coefficients, representing the sensitivity of each spectral line on a variation of the proton-to-electron mass ratio μ = mp/me are derived for all lines in the H2 spectrum. The laboratory wavelengths and Ki's are used in a comparison with a recent set of highly accurate H2 spectral lines observed in the Q 0347-383 and Q 0405-443 quasars yielding a fractional change in the mass-ratio of Δμ/μ, = 2.4 ± 0.6 × 10 -5 (1σ). This result indicates, at a 4σ confidence level, that μ may have decreased in the past 12 billion years.

AB - A novel and highly accurate (at the level of Δλ/λ = 5 × 10-8) database of 233 spectral lines in the Lyman and Werner bands of H2 is determined via laboratory spectroscopy employing a narrowband and tunable extreme ultraviolet laser system. Furthermore an updated set of so-called Ki coefficients, representing the sensitivity of each spectral line on a variation of the proton-to-electron mass ratio μ = mp/me are derived for all lines in the H2 spectrum. The laboratory wavelengths and Ki's are used in a comparison with a recent set of highly accurate H2 spectral lines observed in the Q 0347-383 and Q 0405-443 quasars yielding a fractional change in the mass-ratio of Δμ/μ, = 2.4 ± 0.6 × 10 -5 (1σ). This result indicates, at a 4σ confidence level, that μ may have decreased in the past 12 billion years.

KW - Fundamental constants

KW - Molecular hydrogen

KW - Precision spectroscopy

KW - Quasar absorption

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BT - AIP Conference Proceedings

T2 - 20th International Conference on Atomic Physics, ICAP 2006

Y2 - 16 July 2006 through 21 July 2006

ER -

Precision spectroscopy of H2 and a possible variation of m p/me over cosmological time

Abstract

Conference

Keywords

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