Indication of a Cosmological Variation of the ProtonElectron Mass Ratio Based on Laboratory Measurement and Reanalysis of H_{2} Spectra
Abstract
Based on highly accurate laboratory measurements of Lyman bands of H_{2} and an updated representation of the structure of the ground XΣg+1 and excited BΣu+1 and CΠu1 states, a new set of sensitivity coefficients K_{i} is derived for all lines in the H_{2} spectrum, representing the dependence of their transition wavelengths on a possible variation of the protonelectron mass ratio μ=m_{p}/m_{e}. Included are local perturbation effects between B and C levels and adiabatic corrections. The new wavelengths and K_{i} factors are used to compare with a recent set of highly accurate H_{2} spectral lines observed in the Q 0347383 and Q 0405443 quasars, yielding a fractional change in the mass ratio of Δμ/μ=(2.4±0.6)×10^{5} for a weighted fit and Δμ/μ=(2.0±0.6)×10^{5} for an unweighted fit. This result indicates, at a 3.5σ confidence level, that μ could have decreased in the past 12 Gyr.
 Publication:

Physical Review Letters
 Pub Date:
 April 2006
 DOI:
 10.1103/PhysRevLett.96.151101
 Bibcode:
 2006PhRvL..96o1101R
 Keywords:

 95.30.Dr;
 14.20.Dh;
 33.15.e;
 98.80.k;
 Atomic processes and interactions;
 Protons and neutrons;
 Properties of molecules;
 Cosmology