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Description
Absorption lines of H_2_ and HD molecules observed at high redshift in the line of sight towards quasars are a test ground to search for variation of the proton-to-electron mass ratio {mu}. For this purpose results from astronomical observations are compared with a compilation of molecular data of the highest accuracy, obtained in laboratory studies as well as in first principles calculations. A comprehensive line list is compiled for H_2_ and HD absorption lines in the Lyman (B^1^{Sigma}^+^_u_-X^1^{Sigma}^+^_g_) and Werner (C^1^{Pi}_u_-X^1^{Sigma}^+^_g_) bands systems up to the Lyman cutoff at 912{AA}. Molecular parameters listed for each line i are the transition wavelength {lambda}_i_, the line oscillator strength f_i_, the radiative damping parameter of the excited state {Gamma}_{i}, and the sensitivity coefficient K_i_ for a variation of the proton-to-electron mass ratio. The transition wavelengths {lambda}_i_ for the H_2_ and HD molecules are determined by a variety of advanced high-precision spectroscopic experiments involving narrowband vacuum ultraviolet lasers, Fourier-transform spectrometers and synchrotron radiation sources. Results for the line oscillator strengths f_i_, damping parameters {Gamma}_i_ and sensitivity coefficients K_i_ are obtained in theoretical quantum chemical calculations. A new list of molecular data is compiled for future analyses of cold clouds of hydrogen absorbers, specifically for studies of {mu}-variation from quasar data. The list is applied in a refit of quasar absorption spectra of B0642-5038 and J1237+0647 yielding constraints on a variation of the proton-to-electron mass ratio {Delta}{mu}/{mu} consistent with previous analyses.
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